(Notice: The appearance depends upon language setting or texture.) Following is the case of English and Japanese with Vanilla.

1. Launch Minecraft
2. Click “Multiplayer” or “マルチプレイ“
   
3. Click “Add server” or “サーバー追加“
   
4. Input something into Server Name / サーバー名, and input multi.minecraftuser.jp into Server Address / サーバーアドレス
   
5. Click “Done” or “完了“
   
6. Click the server added
   
7. Click “Join Server” or ” or “サーバーに接続“