Train stations are often seen as thresholds between beginnings and endings, but they also become places where lost objects and forgotten people are left behind. On a rain‑soaked day, Minky Momo boards a train bound for her final destination. During the ride she strikes up a conversation with an old man who is desperately trying to reunite with someone very important to him. When Momo learns that he has left his passport on the train, she decides to help him retrieve it. In the process, she encounters a parallel version of herself and a young girl who needs their assistance. The girl has connections to the station and longs for a resolution to her troubles.