diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..c25ec13
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,4 @@
+CHATWORK_API_TOKEN=
+CHATWORK_ACCESS_TOKEN=
+CHATWORK_CLIENT_ID=
+CHATWORK_CLIENT_SECRET=
diff --git a/.gitignore b/.gitignore
index adb50aa..937c612 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ test/version_tmp
 tmp
 .ruby-gemset
 .ruby-version
+.env
diff --git a/README.md b/README.md
index 5e5cea9..63b0d8c 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,14 @@ ChatWork::Message.create(room_id: 1234, body: "Hello, ChatWork!")
 $ CHATWORK_CLIENT_ID=xxx CHATWORK_CLIENT_SECRET=xxx REFRESH_TOKEN=xxx ruby refresh_access_token.rb
 ```
 
+## Development
+```bash
+cp .env.example .env
+vi .env
+
+./bin/console
+```
+
 ## Contributing
 
 1. Fork it
diff --git a/bin/console b/bin/console
new file mode 100755
index 0000000..1bad6ee
--- /dev/null
+++ b/bin/console
@@ -0,0 +1,10 @@
+#!/usr/bin/env ruby
+
+require "bundler/setup"
+require "chatwork"
+require "dotenv"
+
+Dotenv.load
+
+require "pry"
+Pry.start
diff --git a/chatwork.gemspec b/chatwork.gemspec
index f0f14e0..b70a4d2 100644
--- a/chatwork.gemspec
+++ b/chatwork.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.license       = "MIT"
 
   spec.files         = `git ls-files`.split($INPUT_RECORD_SEPARATOR)
-  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
+  spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
@@ -22,11 +22,13 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "activesupport"
   spec.add_development_dependency "bundler", "~> 1.3"
   spec.add_development_dependency "coveralls"
+  spec.add_development_dependency "dotenv"
   spec.add_development_dependency "onkcop", "0.52.1.0"
   spec.add_development_dependency "pry-byebug"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec"
   spec.add_development_dependency "rspec-its"
+  spec.add_development_dependency "rspec-parameterized"
   spec.add_development_dependency "rubocop", "0.52.1"
   spec.add_development_dependency "rubocop-rspec", "1.21.0"
   spec.add_development_dependency "webmock"
diff --git a/lib/chatwork.rb b/lib/chatwork.rb
index f1448b2..f813c33 100644
--- a/lib/chatwork.rb
+++ b/lib/chatwork.rb
@@ -7,13 +7,15 @@ module ChatWork
   autoload :ChatWorkError,      "chatwork/chatwork_error"
   autoload :Client,             "chatwork/client"
   autoload :Contacts,           "chatwork/contacts"
-  autoload :Entity,             "chatwork/entity"
+  autoload :EntityMethods,      "chatwork/entity_methods"
+  autoload :File,               "chatwork/file"
+  autoload :IncomingRequest,    "chatwork/incoming_request"
   autoload :Me,                 "chatwork/me"
   autoload :Member,             "chatwork/member"
   autoload :Message,            "chatwork/message"
+  autoload :MyStatus,           "chatwork/my_status"
   autoload :MyTask,             "chatwork/my_task"
   autoload :OAuthClient,        "chatwork/oauth_client"
-  autoload :Operations,         "chatwork/operations"
   autoload :Room,               "chatwork/room"
   autoload :Task,               "chatwork/task"
   autoload :Token,              "chatwork/token"
diff --git a/lib/chatwork/base_client.rb b/lib/chatwork/base_client.rb
index bea92b5..aad01fe 100644
--- a/lib/chatwork/base_client.rb
+++ b/lib/chatwork/base_client.rb
@@ -20,7 +20,8 @@ def initialize(api_base, api_version, header)
     def handle_response(response)
       case response.status
       when 204
-        ChatWork::ChatWorkError.from_response(response.status, response.body, response.headers)
+        # HTTP status 204 doesn't return json
+        response.body
       when 200..299
         begin
           JSON.parse(response.body)
diff --git a/lib/chatwork/chatwork_error.rb b/lib/chatwork/chatwork_error.rb
index 3ece01f..ec56e8c 100644
--- a/lib/chatwork/chatwork_error.rb
+++ b/lib/chatwork/chatwork_error.rb
@@ -2,9 +2,6 @@
 module ChatWork
   class ChatWorkError < StandardError
     def self.from_response(status, body, headers)
-      # HTTP status 204 don't have body.
-      return APIError.new(status, "") if status == 204
-
       hash =
         begin
           JSON.parse(body)
diff --git a/lib/chatwork/contacts.rb b/lib/chatwork/contacts.rb
index af49c4d..de6ce93 100644
--- a/lib/chatwork/contacts.rb
+++ b/lib/chatwork/contacts.rb
@@ -1,10 +1,11 @@
 module ChatWork
-  class Contacts < Entity
-    install_class_operations :_get
+  module Contacts
+    extend EntityMethods
 
     # Get the list of your contacts
     #
     # @see http://developer.chatwork.com/ja/endpoint_contacts.html#GET-contacts
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @return [Array<Hash>]
     #
@@ -22,15 +23,7 @@ class Contacts < Entity
     #     }
     #   ]
     def self.get
-      _get
-    end
-
-    def self.path
-      "/contacts"
-    end
-
-    def path
-      "/contacts"
+      _get("/contacts")
     end
   end
 end
diff --git a/lib/chatwork/entity.rb b/lib/chatwork/entity.rb
deleted file mode 100644
index 9ccee99..0000000
--- a/lib/chatwork/entity.rb
+++ /dev/null
@@ -1,33 +0,0 @@
-module ChatWork
-  class Entity
-    class << self
-      include Operations
-      def convert(hash)
-        # not implement
-        # converter = ResponseConverter.new
-        # converter.convert(hash)
-        hash
-      end
-
-      def hash_compact(hash)
-        hash.reject { |_k, v| v.nil? }
-      end
-    end
-
-    attr_reader :attributes
-
-    def initialize(attributes)
-      @attributes = attributes
-    end
-
-    private
-
-      # not implement
-      def update_attributes(attributes)
-        raise "unexpected object" if attributes["object"] != @attributes["object"]
-        new_object = ResponseConverter.new.convert(attributes)
-        @attributes = new_object.attributes
-        self
-      end
-  end
-end
diff --git a/lib/chatwork/entity_methods.rb b/lib/chatwork/entity_methods.rb
new file mode 100644
index 0000000..91db6aa
--- /dev/null
+++ b/lib/chatwork/entity_methods.rb
@@ -0,0 +1,36 @@
+module ChatWork
+  module EntityMethods
+    private
+
+      def _get(path, params = {}, &block)
+        ChatWork.client.get(path, hash_compact(params), &block)
+      end
+
+      def _post(path, params = {}, &block)
+        ChatWork.client.post(path, hash_compact(params), &block)
+      end
+
+      def _put(path, params = {}, &block)
+        ChatWork.client.put(path, hash_compact(params), &block)
+      end
+
+      def _delete(path, params = {}, &block)
+        ChatWork.client.delete(path, hash_compact(params), &block)
+      end
+
+      def hash_compact(hash)
+        hash.reject { |_k, v| v.nil? }
+      end
+
+      def boolean_to_integer(value)
+        case value
+        when true
+          1
+        when false
+          0
+        else
+          value
+        end
+      end
+  end
+end
diff --git a/lib/chatwork/file.rb b/lib/chatwork/file.rb
new file mode 100644
index 0000000..0755824
--- /dev/null
+++ b/lib/chatwork/file.rb
@@ -0,0 +1,63 @@
+module ChatWork
+  module File
+    extend EntityMethods
+
+    # Get the list of files associated with the specified chat
+    #
+    # @param room_id [Integer]
+    # @param account_id [Integer]
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-files
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @return [Array<Hash>]
+    #
+    # @example response format
+    #   [
+    #     {
+    #       "file_id": 3,
+    #       "account": {
+    #         "account_id": 123,
+    #         "name": "Bob",
+    #         "avatar_image_url": "https://example.com/ico_avatar.png"
+    #       },
+    #       "message_id": "22",
+    #       "filename": "README.md",
+    #       "filesize": 2232,
+    #       "upload_time": 1384414750
+    #     }
+    #   ]
+    def self.get(room_id:, account_id:)
+      _get("/rooms/#{room_id}/files", account_id: account_id)
+    end
+
+    # Get information about the specified file
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-files-file_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param file_id [Integer]
+    # @param create_download_url [Boolean] whether or not to create a download link.
+    #                                      If set to true, download like will be created for 30 seconds
+    #
+    # @return [Array<Hash>]
+    #
+    # @example response format
+    #   {
+    #     "file_id":3,
+    #     "account": {
+    #       "account_id":123,
+    #       "name":"Bob",
+    #       "avatar_image_url": "https://example.com/ico_avatar.png"
+    #     },
+    #     "message_id": "22",
+    #     "filename": "README.md",
+    #     "filesize": 2232,
+    #     "upload_time": 1384414750
+    #   }
+    def self.find(room_id:, file_id:, create_download_url: nil)
+      _get("/rooms/#{room_id}/files/#{file_id}", create_download_url: boolean_to_integer(create_download_url))
+    end
+  end
+end
diff --git a/lib/chatwork/incoming_request.rb b/lib/chatwork/incoming_request.rb
new file mode 100644
index 0000000..c9f16e3
--- /dev/null
+++ b/lib/chatwork/incoming_request.rb
@@ -0,0 +1,71 @@
+module ChatWork
+  module IncomingRequest
+    extend EntityMethods
+
+    # You can get the list of contact approval request you received
+    #
+    # (*This method returns up to 100 entries. We are planning to implement pagination to support larger number of data retrieval)
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_incoming_requests.html#GET-incoming_requests
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @return [Array<Hash>]
+    #
+    # @example response format
+    #   [
+    #     {
+    #       "request_id": 123,
+    #       "account_id": 363,
+    #       "message": "hogehoge",
+    #       "name": "John Smith",
+    #       "chatwork_id": "tarochatworkid",
+    #       "organization_id": 101,
+    #       "organization_name": "Hello Company",
+    #       "department": "Marketing",
+    #       "avatar_image_url": "https://example.com/abc.png"
+    #     }
+    #   ]
+    def self.get
+      _get("/incoming_requests")
+    end
+
+    # You can approve a contact approval request you received
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_incoming_requests.html#PUT-incoming_requests-request_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param request_id [Integer]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "account_id": 363,
+    #     "room_id": 1234,
+    #     "name": "John Smith",
+    #     "chatwork_id": "tarochatworkid",
+    #     "organization_id": 101,
+    #     "organization_name": "Hello Company",
+    #     "department": "Marketing",
+    #     "avatar_image_url": "https://example.com/abc.png"
+    #   }
+    def self.update(request_id:)
+      _put("/incoming_requests/#{request_id}")
+    end
+
+    # You can decline a contact approval request you received
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_incoming_requests.html#DELETE-incoming_requests-request_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param request_id [Integer]
+    def self.destroy(request_id:)
+      _delete("/incoming_requests/#{request_id}")
+    end
+
+    class << self
+      alias_method :approve, :update
+      alias_method :decline, :destroy
+    end
+  end
+end
diff --git a/lib/chatwork/me.rb b/lib/chatwork/me.rb
index dbedba5..c7b57bb 100644
--- a/lib/chatwork/me.rb
+++ b/lib/chatwork/me.rb
@@ -1,10 +1,11 @@
 module ChatWork
-  class Me < Entity
-    install_class_operations :_get
+  module Me
+    extend EntityMethods
 
     # Get your account information
     #
     # @see http://developer.chatwork.com/ja/endpoint_me.html#GET-me
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @return [Hash]
     #
@@ -31,15 +32,7 @@ class Me < Entity
     #     "login_mail": "account@example.com"
     #   }
     def self.get
-      _get
-    end
-
-    def self.path
-      "/me"
-    end
-
-    def path
-      "/me"
+      _get("/me")
     end
   end
 end
diff --git a/lib/chatwork/member.rb b/lib/chatwork/member.rb
index 03ff70f..c580ea9 100644
--- a/lib/chatwork/member.rb
+++ b/lib/chatwork/member.rb
@@ -1,10 +1,11 @@
 module ChatWork
-  class Member < Entity
-    install_class_operations :_get
+  module Member
+    extend EntityMethods
 
     # Get the list of all chat members associated with the specified chat
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-members
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param room_id [Integer]
     #
@@ -24,11 +25,36 @@ class Member < Entity
     #     }
     #   ]
     def self.get(room_id:)
-      _get(room_id: room_id)
+      _get("/rooms/#{room_id}/members")
     end
 
-    def self.path
-      "/rooms/%d/members"
+    # Change associated members of group chat at once
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id-members
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param members_admin_ids [Array<Integer>, String] List of user IDs who will be given administrator permission for the group chat.
+    #                                                   At least one user must be specified as an administrator.
+    # @param members_member_ids [Array<Integer>, String] List of user IDs who will be given member permission for the group chat.
+    # @param members_readonly_ids [Array<Integer>, String] List of user IDs who will be given read-only permission for the group chat.
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    # {
+    #   "admin": [123, 542, 1001],
+    #   "member": [10, 103],
+    #   "readonly": [6, 11]
+    # }
+    def self.update_all(room_id:, members_admin_ids:, members_member_ids: nil, members_readonly_ids: nil)
+      params = {
+        members_admin_ids: Array(members_admin_ids).join(","),
+      }
+      params[:members_member_ids] = Array(members_member_ids).join(",") if members_member_ids
+      params[:members_readonly_ids] = Array(members_readonly_ids).join(",") if members_readonly_ids
+
+      _put("/rooms/#{room_id}/members", params)
     end
   end
 end
diff --git a/lib/chatwork/message.rb b/lib/chatwork/message.rb
index c9bf857..264b34d 100644
--- a/lib/chatwork/message.rb
+++ b/lib/chatwork/message.rb
@@ -1,12 +1,13 @@
 module ChatWork
-  class Message < Entity
-    install_class_operations :_create, :_get
+  module Message
+    extend EntityMethods
 
     # Get all messages associated with the specified chat (returns up to 100 entries).
     #
     # If the parameter is not set, it returns the next 100 entries from previous call.
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-messages
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param room_id [Integer]
     # @param force   [Boolean, Integer] Flag which forces to get 100 newest entries regardless of previous calls.
@@ -28,21 +29,13 @@ class Message < Entity
     #     }
     #   ]
     def self.get(room_id:, force: nil)
-      params = { room_id: room_id }
-
-      case force
-      when 1, true
-        params[:force] = 1
-      when 0, false
-        params[:force] = 0
-      end
-
-      _get(params)
+      _get("/rooms/#{room_id}/messages", force: boolean_to_integer(force))
     end
 
     # Add new message to the chat
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#POST-rooms-room_id-messages
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param room_id [Integer]
     # @param body    [String] message body
@@ -54,15 +47,108 @@ def self.get(room_id:, force: nil)
     #     "message_id": "1234"
     #   }
     def self.create(room_id:, body:)
-      _create(room_id: room_id, body: body)
+      _post("/rooms/#{room_id}/messages", body: body)
+    end
+
+    # Mark messages as read
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id-messages-read
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param message_id [String]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "unread_num": 461,
+    #     "mention_num": 0
+    #   }
+    def self.read(room_id:, message_id: nil)
+      _put("/rooms/#{room_id}/messages/read", message_id: message_id)
     end
 
-    def self.path
-      "/rooms/%d/messages"
+    # Mark messages as unread
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id-messages-unread
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param message_id [String]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "unread_num": 3,
+    #     "mention_num": 0
+    #   }
+    def self.unread(room_id:, message_id:)
+      _put("/rooms/#{room_id}/messages/unread", message_id: message_id)
     end
 
-    def path
-      "/rooms/%d/messages"
+    # Get information about the specified message
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-messages-message_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param message_id [String]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "message_id": "5",
+    #     "account": {
+    #       "account_id": 123,
+    #       "name": "Bob",
+    #       "avatar_image_url": "https://example.com/ico_avatar.png"
+    #     },
+    #     "body": "Hello Chatwork!",
+    #     "send_time": 1384242850,
+    #     "update_time": 0
+    #   }
+    def self.find(room_id:, message_id:)
+      _get("/rooms/#{room_id}/messages/#{message_id}")
+    end
+
+    # Update the specified message
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id-messages-message_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param message_id [String]
+    # @param body [String] message body
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "message_id": "1234"
+    #   }
+    def self.update(room_id:, message_id:, body:)
+      _put("/rooms/#{room_id}/messages/#{message_id}", body: body)
+    end
+
+    # Destroy the specified message
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id-messages-message_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param message_id [String]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "message_id": "1234"
+    #   }
+    def self.destroy(room_id:, message_id:)
+      _delete("/rooms/#{room_id}/messages/#{message_id}")
     end
   end
 end
diff --git a/lib/chatwork/my_status.rb b/lib/chatwork/my_status.rb
new file mode 100644
index 0000000..3785a5f
--- /dev/null
+++ b/lib/chatwork/my_status.rb
@@ -0,0 +1,25 @@
+module ChatWork
+  module MyStatus
+    extend EntityMethods
+
+    # Get the number of: unread messages, unread To messages, and unfinished tasks.
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_my.html#GET-my-status
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "unread_room_num": 2,
+    #     "mention_room_num": 1,
+    #     "mytask_room_num": 3,
+    #     "unread_num": 12,
+    #     "mention_num": 1,
+    #     "mytask_num": 8
+    #   }
+    def self.get
+      _get("/my/status")
+    end
+  end
+end
diff --git a/lib/chatwork/my_task.rb b/lib/chatwork/my_task.rb
index 45399c6..5097f37 100644
--- a/lib/chatwork/my_task.rb
+++ b/lib/chatwork/my_task.rb
@@ -1,12 +1,13 @@
 module ChatWork
-  class MyTask < Entity
-    install_class_operations :_get
+  module MyTask
+    extend EntityMethods
 
     # Get the list of all unfinished tasks
     #
     # (*This method returns up to 100 entries. We are planning to implement pagination to support larger number of data retrieval)
     #
     # @see http://developer.chatwork.com/ja/endpoint_my.html#GET-my-tasks
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param assigned_by_account_id [Integer] Account ID of the person who assigned task
     # @param status [String] Task status (open, done)
@@ -34,20 +35,7 @@ class MyTask < Entity
     #     }
     #   ]
     def self.get(assigned_by_account_id: nil, status: nil)
-      params = {
-        assigned_by_account_id: assigned_by_account_id,
-        status:                 status,
-      }
-
-      _get(hash_compact(params))
-    end
-
-    def self.path
-      "/my/tasks"
-    end
-
-    def path
-      "/my/tasks"
+      _get("/my/tasks", assigned_by_account_id: assigned_by_account_id, status: status)
     end
   end
 end
diff --git a/lib/chatwork/operations.rb b/lib/chatwork/operations.rb
deleted file mode 100644
index f088e06..0000000
--- a/lib/chatwork/operations.rb
+++ /dev/null
@@ -1,49 +0,0 @@
-module ChatWork
-  module Operations
-    ACCEPT_PARAMS_ID = %i[file_id task_id message_id].freeze
-
-    attr_accessor :assign_path
-
-    def install_class_operations(*operations)
-      define_create if operations.include?(:_create)
-      define_get if operations.include?(:_get)
-    end
-
-    def define_get
-      instance_eval do
-        def _get(params = {}, &block)
-          @assign_path = parse_if_hash_key_exists(path, params, :room_id)
-          attach_nested_resource_id(params)
-          convert(ChatWork.client.get(@assign_path, params, &block))
-        end
-      end
-    end
-
-    def define_create
-      instance_eval do
-        def _create(params = {}, &block)
-          @assign_path = parse_if_hash_key_exists(path, params, :room_id)
-          attach_nested_resource_id(params)
-          convert(ChatWork.client.post(@assign_path, params, &block))
-        end
-      end
-    end
-
-    private
-
-      def parse_if_hash_key_exists(string, hash, key)
-        if hash.include?(key)
-          string % hash.delete(key)
-        else
-          string
-        end
-      end
-
-      def attach_nested_resource_id(params)
-        ACCEPT_PARAMS_ID.each do |id_name|
-          next unless params.include? id_name
-          @assign_path += "/#{params.delete(id_name)}"
-        end
-      end
-  end
-end
diff --git a/lib/chatwork/room.rb b/lib/chatwork/room.rb
index ed1dd8d..5244f2f 100644
--- a/lib/chatwork/room.rb
+++ b/lib/chatwork/room.rb
@@ -1,10 +1,11 @@
 module ChatWork
-  class Room < Entity
-    install_class_operations :_create, :_get
+  module Room
+    extend EntityMethods
 
     # Get the list of all chats on your account
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @return [Array<Hash>]
     #
@@ -27,7 +28,7 @@ class Room < Entity
     #     }
     #   ]
     def self.get
-      _get
+      _get("/rooms")
     end
 
     # rubocop:disable Metrics/ParameterLists
@@ -35,6 +36,7 @@ def self.get
     # Create a new group chat
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#POST-rooms
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param description [String] Description of the group chat
     # @param icon_preset [String] Type of the group chat icon (group, check, document, meeting, event, project, business,
@@ -61,17 +63,64 @@ def self.create(description: nil, icon_preset: nil, members_admin_ids:, members_
       params[:members_member_ids] = Array(members_member_ids).join(",") if members_member_ids
       params[:members_readonly_ids] = Array(members_readonly_ids).join(",") if members_readonly_ids
 
-      _create(hash_compact(params))
+      _post("/rooms", params)
     end
 
     # rubocop:enable Metrics/ParameterLists
 
-    def self.path
-      "/rooms"
+    # Get chat name, icon, and Type (my, direct, or group)
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "room_id": 123,
+    #     "name": "Group Chat Name",
+    #     "type": "group",
+    #     "role": "admin",
+    #     "sticky": false,
+    #     "unread_num": 10,
+    #     "mention_num": 1,
+    #     "mytask_num": 0,
+    #     "message_num": 122,
+    #     "file_num": 10,
+    #     "task_num": 17,
+    #     "icon_path": "https://example.com/ico_group.png",
+    #     "last_update_time": 1298905200,
+    #     "description": "room description text"
+    #   }
+    def self.find(room_id:)
+      _get("/rooms/#{room_id}")
+    end
+
+    # Change the title and icon type of the specified chat
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#PUT-rooms-room_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param description [String] Description of the group chat
+    # @param icon_preset [String] Type of the group chat icon (group, check, document, meeting, event, project, business,
+    #                             study, security, star, idea, heart, magcup, beer, music, sports, travel)
+    # @param name [String] Title of the group chat.
+    def self.update(room_id:, description: nil, icon_preset: nil, name: nil)
+      _put("/rooms/#{room_id}", description: description, icon_preset: icon_preset, name: name)
     end
 
-    def path
-      "/rooms"
+    # Leave/Delete a group chat
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#DELETE-rooms-room_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param action_type [String] leave from a room or delete a room (leave, delete)
+    def self.destroy(room_id:, action_type:)
+      _delete("/rooms/#{room_id}", action_type: action_type)
     end
   end
 end
diff --git a/lib/chatwork/task.rb b/lib/chatwork/task.rb
index 3bc0860..b8569fe 100644
--- a/lib/chatwork/task.rb
+++ b/lib/chatwork/task.rb
@@ -1,14 +1,16 @@
 module ChatWork
-  class Task < Entity
-    install_class_operations :_get, :_create
+  module Task
+    extend EntityMethods
 
     # Get the list of tasks associated with the specified chat
     #
     # (*This method returns up to 100 entries. We are planning to implement pagination to support larger number of data retrieval)
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-tasks
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param room_id [Integer]
+    # @param account_id [Integer]
     # @param assigned_by_account_id [Integer] Account ID of the person who assigned task
     # @param status [String] Task status (open, done)
     #
@@ -35,18 +37,13 @@ class Task < Entity
     #     }
     #   ]
     def self.get(room_id:, account_id:, assigned_by_account_id: nil, status: nil)
-      params = {
-        room_id:                room_id,
-        account_id:             account_id,
-        assigned_by_account_id: assigned_by_account_id,
-        status:                 status,
-      }
-      _get(hash_compact(params))
+      _get("/rooms/#{room_id}/tasks", account_id: account_id, assigned_by_account_id: assigned_by_account_id, status: status)
     end
 
     # Add a new task to the chat
     #
     # @see http://developer.chatwork.com/ja/endpoint_rooms.html#POST-rooms-room_id-tasks
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
     #
     # @param room_id [Integer]
     # @param body    [String] Task description
@@ -61,16 +58,44 @@ def self.get(room_id:, account_id:, assigned_by_account_id: nil, status: nil)
     #   }
     def self.create(room_id:, body:, to_ids:, limit: nil)
       params = {
-        room_id: room_id,
-        body:    body,
-        to_ids:  Array(to_ids).join(","),
+        body:   body,
+        to_ids: Array(to_ids).join(","),
       }
       params[:limit] = limit.to_i if limit
-      _create(hash_compact(params))
+
+      _post("/rooms/#{room_id}/tasks", params)
     end
 
-    def self.path
-      "/rooms/%d/tasks"
+    # Get information about the specified task
+    #
+    # @see http://developer.chatwork.com/ja/endpoint_rooms.html#GET-rooms-room_id-tasks-task_id
+    # @see http://download.chatwork.com/ChatWork_API_Documentation.pdf
+    #
+    # @param room_id [Integer]
+    # @param task_id [Integer]
+    #
+    # @return [Hash]
+    #
+    # @example response format
+    #   {
+    #     "task_id": 3,
+    #     "account": {
+    #       "account_id": 123,
+    #       "name": "Bob",
+    #       "avatar_image_url": "https://example.com/abc.png"
+    #     },
+    #     "assigned_by_account": {
+    #       "account_id": 456,
+    #       "name": "Anna",
+    #       "avatar_image_url": "https://example.com/def.png"
+    #     },
+    #     "message_id": "13",
+    #     "body": "buy milk",
+    #     "limit_time": 1384354799,
+    #     "status": "open"
+    #   }
+    def self.find(room_id:, task_id:)
+      _get("/rooms/#{room_id}/tasks/#{task_id}")
     end
   end
 end
diff --git a/lib/chatwork/token.rb b/lib/chatwork/token.rb
index 87cc6d1..057ff09 100644
--- a/lib/chatwork/token.rb
+++ b/lib/chatwork/token.rb
@@ -1,5 +1,5 @@
 module ChatWork
-  class Token
+  module Token
     # refresh access_token with refresh_token
     #
     # @param refresh_token [String]
diff --git a/spec/lib/chatwork/entity_methods_spec.rb b/spec/lib/chatwork/entity_methods_spec.rb
new file mode 100644
index 0000000..1e78b45
--- /dev/null
+++ b/spec/lib/chatwork/entity_methods_spec.rb
@@ -0,0 +1,21 @@
+describe ChatWork::EntityMethods do
+  include ChatWork::EntityMethods
+
+  describe "#boolean_to_integer" do
+    subject { boolean_to_integer(value) }
+
+    using RSpec::Parameterized::TableSyntax
+
+    where(:value, :expected) do
+      false | 0
+      true  | 1
+      0     | 0
+      1     | 1
+      nil   | nil
+    end
+
+    with_them do
+      it { should eq expected }
+    end
+  end
+end
diff --git a/spec/lib/chatwork/file_spec.rb b/spec/lib/chatwork/file_spec.rb
new file mode 100644
index 0000000..f078d00
--- /dev/null
+++ b/spec/lib/chatwork/file_spec.rb
@@ -0,0 +1,37 @@
+describe ChatWork::File do
+  describe ".get", type: :api do
+    subject { ChatWork::File.get(room_id: room_id, account_id: account_id) }
+
+    before do
+      stub_chatwork_request(:get, "/rooms/#{room_id}/files", "/rooms/{room_id}/files")
+    end
+
+    let(:room_id)    { 123 }
+    let(:account_id) { 101 }
+
+    it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/files"
+  end
+
+  describe ".find", type: :api do
+    subject { ChatWork::File.find(room_id: room_id, file_id: file_id, create_download_url: create_download_url) }
+
+    before do
+      stub_chatwork_request(:get, "/rooms/#{room_id}/files/#{file_id}", "/rooms/{room_id}/files/{file_id}")
+    end
+
+    let(:room_id) { 123 }
+    let(:file_id) { 101 }
+
+    context "when force is Integer" do
+      let(:create_download_url) { 1 }
+
+      it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/files/{file_id}"
+    end
+
+    context "when force is boolean" do
+      let(:create_download_url) { true }
+
+      it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/files/{file_id}"
+    end
+  end
+end
diff --git a/spec/lib/chatwork/incoming_request_spec.rb b/spec/lib/chatwork/incoming_request_spec.rb
new file mode 100644
index 0000000..e4926b6
--- /dev/null
+++ b/spec/lib/chatwork/incoming_request_spec.rb
@@ -0,0 +1,35 @@
+describe ChatWork::IncomingRequest do
+  describe ".get", type: :api do
+    subject { ChatWork::IncomingRequest.get }
+
+    before do
+      stub_chatwork_request(:get, "/incoming_requests")
+    end
+
+    it_behaves_like :a_chatwork_api, :get, "/incoming_requests"
+  end
+
+  describe ".update", type: :api do
+    subject { ChatWork::IncomingRequest.update(request_id: request_id) }
+
+    let(:request_id) { 123 }
+
+    before do
+      stub_chatwork_request(:put, "/incoming_requests/#{request_id}", "/incoming_requests/{request_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :put, "/incoming_requests/{request_id}"
+  end
+
+  describe ".destroy", type: :api do
+    subject { ChatWork::IncomingRequest.destroy(request_id: request_id) }
+
+    let(:request_id) { 123 }
+
+    before do
+      stub_chatwork_request(:delete, "/incoming_requests/#{request_id}", "/incoming_requests/{request_id}", 204)
+    end
+
+    it_behaves_like :a_chatwork_api, :delete, "/incoming_requests/{request_id}", 204
+  end
+end
diff --git a/spec/lib/chatwork/member_spec.rb b/spec/lib/chatwork/member_spec.rb
index 7caeb7e..34405d4 100644
--- a/spec/lib/chatwork/member_spec.rb
+++ b/spec/lib/chatwork/member_spec.rb
@@ -10,4 +10,37 @@
 
     it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/members"
   end
+
+  describe ".update_all", type: :api do
+    subject do
+      ChatWork::Member.update_all(
+        room_id:              room_id,
+        members_admin_ids:    members_admin_ids,
+        members_member_ids:   members_member_ids,
+        members_readonly_ids: members_readonly_ids,
+      )
+    end
+
+    let(:room_id) { 123 }
+
+    before do
+      stub_chatwork_request(:put, "/rooms/#{room_id}/members", "/rooms/{room_id}/members")
+    end
+
+    context "with String" do
+      let(:members_admin_ids)    { "123,542,1001" }
+      let(:members_member_ids)   { "21,344" }
+      let(:members_readonly_ids) { "15,103" }
+
+      it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}/members"
+    end
+
+    context "with Array" do
+      let(:members_admin_ids)    { [123, 542, 1001] }
+      let(:members_member_ids)   { [21, 344] }
+      let(:members_readonly_ids) { [15, 103] }
+
+      it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}/members"
+    end
+  end
 end
diff --git a/spec/lib/chatwork/message_spec.rb b/spec/lib/chatwork/message_spec.rb
index 1e3d6cc..6d5783a 100644
--- a/spec/lib/chatwork/message_spec.rb
+++ b/spec/lib/chatwork/message_spec.rb
@@ -33,4 +33,70 @@
 
     it_behaves_like :a_chatwork_api, :post, "/rooms/{room_id}/messages"
   end
+
+  describe ".read", type: :api do
+    subject { ChatWork::Message.read(room_id: room_id, message_id: message_id) }
+
+    let(:room_id)    { 123 }
+    let(:message_id) { "101" }
+
+    before do
+      stub_chatwork_request(:put, "/rooms/#{room_id}/messages/read", "/rooms/{room_id}/messages/read")
+    end
+
+    it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}/messages/read"
+  end
+
+  describe ".unread", type: :api do
+    subject { ChatWork::Message.unread(room_id: room_id, message_id: message_id) }
+
+    let(:room_id)    { 123 }
+    let(:message_id) { "101" }
+
+    before do
+      stub_chatwork_request(:put, "/rooms/#{room_id}/messages/unread", "/rooms/{room_id}/messages/unread")
+    end
+
+    it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}/messages/unread"
+  end
+
+  describe ".find", type: :api do
+    subject { ChatWork::Message.find(room_id: room_id, message_id: message_id) }
+
+    let(:room_id)    { 123 }
+    let(:message_id) { "101" }
+
+    before do
+      stub_chatwork_request(:get, "/rooms/#{room_id}/messages/#{message_id}", "/rooms/{room_id}/messages/{message_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/messages/{message_id}"
+  end
+
+  describe ".update", type: :api do
+    subject { ChatWork::Message.update(room_id: room_id, message_id: message_id, body: body) }
+
+    let(:room_id)    { 123 }
+    let(:message_id) { "101" }
+    let(:body)       { "Hello ChatWork!" }
+
+    before do
+      stub_chatwork_request(:put, "/rooms/#{room_id}/messages/#{message_id}", "/rooms/{room_id}/messages/{message_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}/messages/{message_id}"
+  end
+
+  describe ".destroy", type: :api do
+    subject { ChatWork::Message.destroy(room_id: room_id, message_id: message_id) }
+
+    let(:room_id)    { 123 }
+    let(:message_id) { "101" }
+
+    before do
+      stub_chatwork_request(:delete, "/rooms/#{room_id}/messages/#{message_id}", "/rooms/{room_id}/messages/{message_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :delete, "/rooms/{room_id}/messages/{message_id}"
+  end
 end
diff --git a/spec/lib/chatwork/my_status_spec.rb b/spec/lib/chatwork/my_status_spec.rb
new file mode 100644
index 0000000..630cf9d
--- /dev/null
+++ b/spec/lib/chatwork/my_status_spec.rb
@@ -0,0 +1,13 @@
+describe ChatWork::MyStatus do
+  describe ".get", type: :api do
+    subject do
+      ChatWork::MyStatus.get
+    end
+
+    before do
+      stub_chatwork_request(:get, "/my/status")
+    end
+
+    it_behaves_like :a_chatwork_api, :get, "/my/status"
+  end
+end
diff --git a/spec/lib/chatwork/room_spec.rb b/spec/lib/chatwork/room_spec.rb
index 792a11f..3cd7997 100644
--- a/spec/lib/chatwork/room_spec.rb
+++ b/spec/lib/chatwork/room_spec.rb
@@ -47,4 +47,56 @@
       it_behaves_like :a_chatwork_api, :post, "/rooms"
     end
   end
+
+  describe ".find", type: :api do
+    subject { ChatWork::Room.find(room_id: room_id) }
+
+    let(:room_id) { 123 }
+
+    before do
+      stub_chatwork_request(:get, "/rooms/#{room_id}", "/rooms/{room_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}"
+  end
+
+  describe ".update", type: :api do
+    subject do
+      ChatWork::Room.update(
+        room_id:     room_id,
+        description: description,
+        icon_preset: icon_preset,
+        name:        name,
+      )
+    end
+
+    let(:room_id)     { 123 }
+    let(:description) { "group chat description" }
+    let(:icon_preset) { "meeting" }
+    let(:name)        { "Website renewal project" }
+
+    before do
+      stub_chatwork_request(:put, "/rooms/#{room_id}", "/rooms/{room_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :put, "/rooms/{room_id}"
+  end
+
+  describe ".destroy", type: :api do
+    subject do
+      ChatWork::Room.destroy(
+        room_id:     room_id,
+        action_type: action_type,
+      )
+    end
+
+    let(:room_id)     { 123 }
+    let(:action_type) { "leave" }
+
+    before do
+      stub_chatwork_request(:delete, "/rooms/#{room_id}", "/rooms/{room_id}", 204)
+    end
+
+    it_behaves_like :a_chatwork_api, :delete, "/rooms/{room_id}", 204
+  end
 end
diff --git a/spec/lib/chatwork/task_spec.rb b/spec/lib/chatwork/task_spec.rb
index cd9cb2f..1b39c49 100644
--- a/spec/lib/chatwork/task_spec.rb
+++ b/spec/lib/chatwork/task_spec.rb
@@ -56,4 +56,22 @@
       it_behaves_like :a_chatwork_api, :post, "/rooms/{room_id}/tasks"
     end
   end
+
+  describe ".find", type: :api do
+    subject do
+      ChatWork::Task.find(
+        room_id: room_id,
+        task_id: task_id,
+      )
+    end
+
+    let(:room_id) { 123 }
+    let(:task_id) { 3 }
+
+    before do
+      stub_chatwork_request(:get, "/rooms/#{room_id}/tasks/#{task_id}", "/rooms/{room_id}/tasks/{task_id}")
+    end
+
+    it_behaves_like :a_chatwork_api, :get, "/rooms/{room_id}/tasks/{task_id}"
+  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index ef678e1..02d9c9d 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -7,6 +7,7 @@
 
 require "chatwork"
 
+require "rspec-parameterized"
 require "rspec/its"
 require "webmock/rspec"
 require "pry"
diff --git a/spec/support/contexts/api_context.rb b/spec/support/contexts/api_context.rb
index 81abb9b..8e05441 100644
--- a/spec/support/contexts/api_context.rb
+++ b/spec/support/contexts/api_context.rb
@@ -28,7 +28,7 @@ def stub_chatwork_request(expected_verb, expected_path, resource_path = nil, sta
     query_example = RamlParser.find_query_parameter_example(expected_verb, resource_path)
     unless query_example.empty?
       case expected_verb
-      when :get
+      when :get, :delete
         query_string = "?" + query_example.to_query
       when :post, :put
         request_options[:headers]["Content-Type"] = "application/x-www-form-urlencoded"
diff --git a/spec/support/matchers/match_example.rb b/spec/support/matchers/match_example.rb
index e3c4c08..5882c86 100644
--- a/spec/support/matchers/match_example.rb
+++ b/spec/support/matchers/match_example.rb
@@ -8,6 +8,6 @@
 
   description do
     expected_example = RamlParser.find_response_example(verb, resource, status)
-    "match #{expected_example}"
+    "match '#{expected_example}'"
   end
 end
diff --git a/spec/support/utils/raml_parser.rb b/spec/support/utils/raml_parser.rb
index 750aa0b..0d36bd0 100644
--- a/spec/support/utils/raml_parser.rb
+++ b/spec/support/utils/raml_parser.rb
@@ -10,7 +10,7 @@ def self.find_response_example(verb, path, status = 200)
     return nil unless resource
 
     response_json = resource.dig("responses", status, "body", "application/json", "example")
-    return JSON.parse(response_json) if response_json
+    return parse_response(response_json) if response_json
 
     return nil unless resource["is"]
 
@@ -19,7 +19,7 @@ def self.find_response_example(verb, path, status = 200)
       next unless trait
 
       response_json = trait.dig("responses", status, "body", "application/json", "example")
-      return JSON.parse(response_json) if response_json
+      return parse_response(response_json) if response_json
     end
 
     nil
@@ -76,4 +76,11 @@ def self.raml
 
     @raml = YAML.safe_load(yaml_data)
   end
+
+  def self.parse_response(response_json)
+    JSON.parse(response_json)
+  rescue JSON::ParserError
+    response_json
+  end
+  private_class_method :parse_response
 end