Shota, a Japanese businessman in his fifties, leaves for what he believes will be his final business trip, carrying a resignation letter he cannot bring himself to submit. Meanwhile, Daesung, a young Korean man nursing the pain of a recent breakup, travels alone to Enoshima, Japan, hoping to reconnect with a love he has lost. On the first night of their journeys, the two strangers meet by chance at a small ramen shop in Enoshima. Over drinks, they share fragments of their lives and, half in jest, promise to deliver each other's unsent letters—Shota taking Daesung's love letter, and Daesung carrying Shota's resignation letter. What begins as a lighthearted agreement quietly draws both men into one another's emotional worlds, leading them to confront feelings they have long avoided.