High school student Jin Ikawa visits Enoshima during spring break, where he meets Nagi Hibino, a student attending high school in Shonan. The friendship that blossoms between them soon develops into love, and they begin to affirm their feelings for each other. However, as Jin's university graduation approaches, Nagi suddenly tells him, "I can't see a future for us together," and breaks up with him. Thirteen years after their first meeting, Jin is living quietly alone in the countryside, afraid of being known as gay by those around him. One day, Nagi suddenly reappears, bringing along his 6-year-old daughter, Sora. Jin is bewildered when Nagi asks, "Can we stay with you for a while?" but eventually, Sora grows attached to him, and the people around them begin to accept the three of them. During this time, Nagi confides in Jin that he is in the midst of divorce and custody negotiations with his wife, Rena. One day, Rena takes Sora back to Tokyo. As Nagi sinks into despair, Jin expresses his feelings, saying, "I want the three of us—Nagi, Sora, and me—to live together." However, as the divorce proceedings progress, Jin and Nagi are faced with hurtful words from Rena’s lawyer and the judge, forcing them to confront the reality of the environment surrounding them.