In his fifth year of marriage, Hiroki begins to grow increasingly troubled by his wife's drinking habits. One day, he happens to cross paths with his neighbor, Yuri, on his way home, and a casual conversation sparks between them. At first, they exchange lighthearted talk about daily life and current events, but gradually their discussions shift toward deeper topics—marital struggles and family issues. Yuri confides that her husband is constantly busy with night shifts, their relationship has deteriorated, and they haven't had sex in a long time. Though she's merely venting, Hiroki finds an unexpected sense of relief in listening to her. Then, suddenly, Yuri sends him a self-filmed video. Shocked and confused, Hiroki is simultaneously aroused by what he sees. Soon after, he receives a direct invitation from her. Despite never having cheated on his wife, Hiroki finds himself drawn in by Yuri's words. Wrestling with guilt, he still ends up visiting her—leading to a full-blown affair. Though he knows it should end, he becomes increasingly captivated by Yuri's allure. As their illicit relationship continues, a strange phenomenon begins to unfold…