Konya F Ji, Ni Nin No Kimi Ga Iru Eki He. (Media Works Bunko Yo 2-3) [Light Novel]

[Machine Translation] One night near Christmas. The second car of the last Keihin Tohoku Line train on which Subaru boarded suddenly disappeared. Subaru finds himself at Takanawa Gateway Station, a station that has not yet opened to traffic, five years in the future. Subaru had lost his beloved girlfriend in the lost time. Then there are the five passengers Hitomi, Yusaku, Chenjo, and Shintaro, who are in various circumstances. Unable to catch up with the changed future, Subaru and his friends learn that there is a possibility to go back to the past. However, only one of them can go back.

クリスマス間近のある夜。昴の乗った京浜東北線最終電車の第2車両が、突如消え去った。気づいた昴がいた場所は、まだ開通してないはずの高輪ゲートウェイ駅―そこは5年後の未来だった。失われた時間に、最愛の彼女を亡くしていた昴。そして、様々な事情を抱える瞳、勇作、晟生、真太郎の乗客たち五人。変わり果てた未来に追いつけないでいた昴たちは、過去に戻れる可能性があることを知る。ただし、戻れるのは一人だけ―。