on rightclick on sign:
    line 2 of clicked block is "checkpoint"
    line 3 of clicked block is "[rightclick]"
    set {checkpoint.%player%} to location of player
    message "&6チェックポイントを設定しました!"
   if player has permission "skript.admin":
       message "&7Location of player"
on rightclick with nether star:
   cancel event
   if clicked block is sign:
       stop
   if {checkpoint.%player%} is set:
       teleport player to {checkpoint.%player%}
       stop
   else:
       message "&cチェックポイントが設定されていません!"