command /gmi:
   usage: /gmi
   permission: command.gmi
   trigger:
      if player has permission "command.gmi":
         give player diamond named "&aゲームモード変更"

on rightclick holding a diamond:
   if player has permission "creative.sk":
      if player's tool is diamond named "&aゲームモード変更":
         if player's gamemode is survival:
            set the player's gamemode to creative
            stop
         if player's gamemode is creative:
            set the player's gamemode to survival
         stop
      else:
         stop