diff --git a/client/package.json b/client/package.json
index bdede799d..ee6e4d997 100644
--- a/client/package.json
+++ b/client/package.json
@@ -20,6 +20,7 @@
     "jquery-binarytransport": "1.0.0",
     "lodash": "4.17.21",
     "moment": "2.29.1",
+    "moment-locales-webpack-plugin": "^1.2.0",
     "normalize.css": "8.0.1",
     "omggif": "1.0.10",
     "pako": "2.0.4",
diff --git a/client/webpack.config.js b/client/webpack.config.js
index 1070e3f55..173f645e8 100644
--- a/client/webpack.config.js
+++ b/client/webpack.config.js
@@ -2,6 +2,7 @@ const path = require('path');
 
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+const MomentLocalesPlugin = require('moment-locales-webpack-plugin');
 const webpack = require('webpack');
 
 const SRC_PATH = path.resolve(__dirname, './src');
@@ -73,6 +74,9 @@ const config = {
       inject: false,
       template: path.resolve(SRC_PATH, './index.html'),
     }),
+    new MomentLocalesPlugin({
+      localesToKeep: ['ja'],
+  }),
   ],
   resolve: {
     extensions: ['.js', '.jsx'],
diff --git a/yarn.lock b/yarn.lock
index a8af3e637..b6ba53fd4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3878,6 +3878,11 @@ lodash.debounce@^4.0.8:
   resolved "https://registry.yarnpkg.com/lodash.debounce/-/lodash.debounce-4.0.8.tgz#82d79bff30a67c4005ffd5e2515300ad9ca4d7af"
   integrity sha1-gteb/zCmfEAF/9XiUVMArZyk168=
 
+lodash.difference@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.difference/-/lodash.difference-4.5.0.tgz#9ccb4e505d486b91651345772885a2df27fd017c"
+  integrity sha1-nMtOUF1Ia5FlE0V3KIWi3yf9AXw=
+
 lodash.flattendeep@^4.0.0:
   version "4.4.0"
   resolved "https://registry.yarnpkg.com/lodash.flattendeep/-/lodash.flattendeep-4.4.0.tgz#fb030917f86a3134e5bc9bec0d69e0013ddfedb2"
@@ -4087,6 +4092,13 @@ modern-normalize@^1.1.0:
   resolved "https://registry.yarnpkg.com/modern-normalize/-/modern-normalize-1.1.0.tgz#da8e80140d9221426bd4f725c6e11283d34f90b7"
   integrity sha512-2lMlY1Yc1+CUy0gw4H95uNN7vjbpoED7NNRSBHE25nWfLBdmMzFCsPshlzbxHz+gYMcBEUN8V4pU16prcdPSgA==
 
+moment-locales-webpack-plugin@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/moment-locales-webpack-plugin/-/moment-locales-webpack-plugin-1.2.0.tgz#9af83876a44053706b868ceece5119584d10d7aa"
+  integrity sha512-QAi5v0OlPUP7GXviKMtxnpBAo8WmTHrUNN7iciAhNOEAd9evCOvuN0g1N7ThIg3q11GLCkjY1zQ2saRcf/43nQ==
+  dependencies:
+    lodash.difference "^4.5.0"
+
 moment-timezone@^0.5.31:
   version "0.5.34"
   resolved "https://registry.yarnpkg.com/moment-timezone/-/moment-timezone-0.5.34.tgz#a75938f7476b88f155d3504a9343f7519d9a405c"