diff --git a/README.md b/README.md
index 45ad509a..43fa6490 100644
--- a/README.md
+++ b/README.md
@@ -89,11 +89,19 @@ Repository url where you want to install:
 
 ## アップデート
 
-`update.sh` を実行します。
-
-```sh
-$ ./update.sh
-```
+1. サーバーのバックアップを取る
+1. サーバーを停止する
+    ```sh
+    $ sudo systemctl stop yourserver.example.com
+    ```
+1. `update.sh` を実行し、表示される指示に従う
+    ```sh
+    $ ./update.sh
+    ```
+1. サーバーを起動して動作を確認する
+    ```sh
+    $ sudo systemctl start yourserver.example.com
+    ```
 
 ## Firefish（フォーク元）からの乗り換え
 
@@ -121,9 +129,10 @@ $ ./update.sh
     $ cp -r calckey.old/custom calckey
     $ cp -r calckey.old/.config calckey
     ```
-1. ビルドする
+1. 新しい Firefish のディレクトリに入ってビルドする
     ```sh
-    $ ./calckey/update.sh
+    $ cd calckey
+    $ ./update.sh
     ```
 1. サーバーを起動して動作を確認する
     ```sh
@@ -131,6 +140,7 @@ $ ./update.sh
     ```
 1. 元々 Firefish がインストールされていたディレクトリを削除する
     ```sh
+    $ cd ..
     $ rm -rf calckey.old
     ```
 
diff --git a/update.sh b/update.sh
index fbe2ef50..a5300ffa 100755
--- a/update.sh
+++ b/update.sh
@@ -1,15 +1,114 @@
 #!/usr/bin/env bash
-function copy_missing_file {
-  [ -f "packages/backend/native-utils/built/index.js" ] || \
-  cp packages/index.js packages/backend/native-utils/built/index.js
+set -eu
+
+function say {
+  tput setaf 5
+  echo -e "( ^-^) < $1"
+  tput setaf 7
 }
 
-git checkout -- package.json packages/backend/assets && \
-git pull --ff && \
-COMMIT=$(git rev-parse --short HEAD) && \
-sed -i -r "s/\"version\": \"([^+]+).*\",$/\"version\": \"\\1+neko:${COMMIT}\",/" package.json && \
-corepack prepare pnpm@latest --activate && \
-pnpm i && \
-NODE_ENV=production pnpm run rebuild && \
-copy_missing_file && \
+function running {
+  tput setaf 3
+  echo "[running] \$ $1"
+  tput setaf 7
+}
+
+say "Start updating!"
+say "Did you stop your server?"
+read -r -p "[Y/n] > " yn
+case "${yn}" in
+  [Nn]|[Nn][Oo])
+    say "You must stop your server first!"
+    exit 1
+    ;;
+  *)
+    say "uwu~ erai erai!\n"
+    ;;
+esac
+
+# Pull changes
+## git pull
+OLD_COMMIT=$(git rev-parse --short HEAD)
+say "Currently we're on \`${OLD_COMMIT}\`"
+
+say "Pulling changes from the remote repo..."
+
+running "git checkout -- package.json packages/backend/assets"
+git checkout -- package.json packages/backend/assets
+
+running "git pull --ff --no-edit --autostash --strategy-option theirs"
+git pull --ff --no-edit --autostash --strategy-option theirs
+
+NEW_COMMIT=$(git rev-parse --short HEAD)
+say "Pulled successfully! Now we're on \`${NEW_COMMIT}\`\n"
+
+## check if the update script itself is updated
+say "Checking if the update script itself has been changed by this update..."
+if [[ $(git diff ${OLD_COMMIT} ${NEW_COMMIT} update.sh) != "" ]]; then
+  say "Oh meow, that seems to be the case."
+  say "I'm sorry to bother you, but please run this script again!"
+  exit 1
+else
+  say "This script seems to be up-to-date!\n"
+fi
+
+## write version info
+say "Writing version info to package.json..."
+
+running "sed -i -r 's/\"version\": \"([^+]+).*\",$/\"version\": \"\\1+neko:${NEW_COMMIT}\",/' package.json"
+sed -i -r "s/\"version\": \"([^+]+).*\",$/\"version\": \"\\1+neko:${NEW_COMMIT}\",/" package.json
+
+say "Done!\n"
+
+# upgrade
+## install dependencies
+say "Upgrading dependencies..."
+
+running "corepack prepare pnpm@latest --activate"
+corepack prepare pnpm@latest --activate
+
+running "pnpm install"
+pnpm install
+
+say "Done!\n"
+
+## build
+say "Start building Firefish."
+say "It takes some time! Why not brew a cup of cofe?"
+
+running "NODE_ENV=production pnpm run rebuild"
+NODE_ENV=production pnpm run rebuild
+
+say "Done! We're almost there.\n"
+
+## prevent migration errors
+if [[ ! -f packages/backend/native-utils/built/index.js ]]; then
+  say "Something went wrong orz... Gonnya try fixing that."
+  pushd
+  running "pushd; cd packages/backend/native-utils; NODE_ENV=production pnpm build; popd"
+  cd packages/backend/native-utils
+  NODE_ENV=production pnpm build
+  popd
+
+  if [[ ! -f packages/backend/native-utils/built/index.js ]]; then
+    say "Something is still broken... I'll take another measure."
+    running "cp packages/index.js packages/backend/native-utils/built/index.js"
+    cp packages/index.js packages/backend/native-utils/built/index.js
+    say "Let's see if it works...\n"
+  else
+    say "The issue seems to be fixed!\n"
+  fi
+else
+  say "It's going well so far!\n"
+fi
+
+## migrate
+say "Database migration time!"
+
+running "pnpm run migrate"
 pnpm run migrate
+
+say "Done!\n"
+
+# Done
+say "Enjoy your sabakan life~"