Formal — to staff
Train · Station
You
反対方向の電車に乗ってしまったのですが、改札を出ずに戻れますか？
はんたいほうこうのでんしゃにのってしまったのですが、かいさつをでずにもどれますか？
I accidentally got on a train going in the opposite direction. Can I head back without passing through the ticket gates?
Romaji: Hantai hoko no densha ni notte shimatta no desu ga, kaisatsu o dezu ni modoremasu ka? / Reply Romaji: Hai, kaidan o watatte mukaigawa no homu ni ikeba, sonomama modoremasu yo.
Reply
はい、階段を渡って向かい側のホームに行けば、そのまま戻れますよ。
はい、かいだんをわたってむかいがわのほーむにいけば、そのままもどれますよ。
Yes, if you use the stairs to go to the opposite platform, you can head back just like that.
Gesture & etiquette
Point back in the general direction you came from or look toward the stairs/bridge.
Do not exit the ticket gates (IC card touch gates) unless instructed, or you will be charged extra. Ask station staff or check the platform signs first.