diff --git a/README.md b/README.md
index ebb4a56..28ac9b7 100644
--- a/README.md
+++ b/README.md
@@ -77,14 +77,15 @@ $ go get git@github.com/tamada/rrh.git
 Usage: rrh [--version] [--help] <command> [<args>]
 
 Available commands are:
-    add          add repositories on the local path to RRH
-    clone        run "git clone" and register it to a group
+    add          add repositories on the local path to RRH.
+    clone        run "git clone" and register it to a group.
     config       set/unset and list configuration of RRH.
     export       export RRH database to stdout.
-    fetch        run "git fetch" on the repositories of the given groups
-    fetch-all    run "git fetch" in the all repositories
+    fetch        run "git fetch" on the repositories of the given groups.
+    fetch-all    run "git fetch" in the all repositories.
     group        add/list/update/remove groups.
     list         print managed repositories and their groups.
+    mv           move the repositories from groups to another group.
     prune        prune unnecessary repositories and groups.
     rm           remove given repository from database.
     status       show git status of repositories.
diff --git a/add/add_cmd.go b/add/add_cmd.go
index 1f0a7d4..e3245b7 100644
--- a/add/add_cmd.go
+++ b/add/add_cmd.go
@@ -102,5 +102,5 @@ func (add *AddCommand) parse(args []string, config *common.Config) (*addOptions,
 Synopsis returns the simple help message of the command.
 */
 func (add *AddCommand) Synopsis() string {
-	return "add repositories on the local path to RRH"
+	return "add repositories on the local path to RRH."
 }
diff --git a/add/add_test.go b/add/add_test.go
index 73cd953..5bbb335 100644
--- a/add/add_test.go
+++ b/add/add_test.go
@@ -27,7 +27,7 @@ func TestInvalidOptions(t *testing.T) {
 
 func TestHelpAndSynopsis(t *testing.T) {
 	var command, _ = AddCommandFactory()
-	if command.Synopsis() != "add repositories on the local path to RRH" {
+	if command.Synopsis() != "add repositories on the local path to RRH." {
 		t.Error("synopsis did not match")
 	}
 	if command.Help() != `rrh add [OPTIONS] <REPOSITORY_PATHS...>
diff --git a/clone/clone_cmd.go b/clone/clone_cmd.go
index 3a30eef..783c8bf 100644
--- a/clone/clone_cmd.go
+++ b/clone/clone_cmd.go
@@ -45,7 +45,7 @@ ARGUMENTS
 Synopsis returns the help message of the command.
 */
 func (clone *CloneCommand) Synopsis() string {
-	return "run \"git clone\" and register it to a group"
+	return "run \"git clone\" and register it to a group."
 }
 
 func (clone *CloneCommand) printIfVerbose(message string) {
diff --git a/clone/clone_test.go b/clone/clone_test.go
index b4f3be5..5d7aec6 100644
--- a/clone/clone_test.go
+++ b/clone/clone_test.go
@@ -164,7 +164,7 @@ ARGUMENTS
 		t.Error("help message did not match")
 	}
 
-	if clone.Synopsis() != `run "git clone" and register it to a group` {
+	if clone.Synopsis() != `run "git clone" and register it to a group.` {
 		t.Error("synopsis did not match")
 	}
 }
diff --git a/common/database.go b/common/database.go
index 1aacec6..79fb2f4 100644
--- a/common/database.go
+++ b/common/database.go
@@ -204,9 +204,7 @@ func (db *Database) UpdateGroup(groupID string, newGroup Group) bool {
 	}
 	for i, group := range db.Groups {
 		if group.Name == groupID {
-			db.Groups[i].Name = newGroup.Name
-			db.Groups[i].Description = newGroup.Description
-			db.Groups[i].OmitList = newGroup.OmitList
+			db.updateGroupImpl(i, groupID, newGroup)
 		}
 	}
 	sortIfNeeded(db)
@@ -214,6 +212,17 @@ func (db *Database) UpdateGroup(groupID string, newGroup Group) bool {
 	return true
 }
 
+func (db *Database) updateGroupImpl(index int, groupID string, newGroup Group) {
+	db.Groups[index].Name = newGroup.Name
+	db.Groups[index].Description = newGroup.Description
+	db.Groups[index].OmitList = newGroup.OmitList
+	for i, relation := range db.Relations {
+		if relation.GroupName == groupID {
+			db.Relations[i].GroupName = newGroup.Name
+		}
+	}
+}
+
 /*
 Relate create the relation between the group and the repository.
 The group and the repository are specified by the given parameters.
diff --git a/fetch/fetch_all_cmd.go b/fetch/fetch_all_cmd.go
index dd5a06e..512893d 100644
--- a/fetch/fetch_all_cmd.go
+++ b/fetch/fetch_all_cmd.go
@@ -104,5 +104,5 @@ func (fetch *FetchAllCommand) parse(args []string) (*FetchOptions, error) {
 Synopsis returns the help message of the command.
 */
 func (fetch *FetchAllCommand) Synopsis() string {
-	return "run \"git fetch\" in the all repositories"
+	return "run \"git fetch\" in the all repositories."
 }
diff --git a/fetch/fetch_cmd.go b/fetch/fetch_cmd.go
index d26ff97..6d1ccad 100644
--- a/fetch/fetch_cmd.go
+++ b/fetch/fetch_cmd.go
@@ -26,7 +26,7 @@ ARGUMENTS
 }
 
 func (fetch *FetchCommand) Synopsis() string {
-	return "run \"git fetch\" on the given groups"
+	return "run \"git fetch\" on the given groups."
 }
 
 func (fetch *FetchCommand) Run(args []string) int {
diff --git a/move/move_cmd.go b/move/move_cmd.go
index 8896b5e..15963f2 100644
--- a/move/move_cmd.go
+++ b/move/move_cmd.go
@@ -289,5 +289,5 @@ ARGUMENTS
 Synopsis returns the help message of the command.
 */
 func (mv *MoveCommand) Synopsis() string {
-	return "move the repositories from groups to another group"
+	return "move the repositories from groups to another group."
 }
diff --git a/move/move_test.go b/move/move_test.go
index b6d35eb..e3d73d0 100644
--- a/move/move_test.go
+++ b/move/move_test.go
@@ -175,8 +175,8 @@ func TestMergeType(t *testing.T) {
 
 func TestSynopsis(t *testing.T) {
 	var mv, _ = MoveCommandFactory()
-	if mv.Synopsis() != "move the repositories from groups to another group" {
-		t.Error("Synopsis message is not matched.")
+	if mv.Synopsis() != "move the repositories from groups to another group." {
+		t.Error("Synopsis message is not matched")
 	}
 }
 
@@ -190,6 +190,6 @@ ARGUMENTS
     FROMS...        specifies move from, formatted in <GROUP_NAME/REPO_ID>, or <GROUP_NAME>
     TO              specifies move to, formatted in <GROUP_NAME>`
 	if mv.Help() != helpMessage {
-		t.Error("Help message is not matched.")
+		t.Error("Help message is not matched")
 	}
 }