Rimi Arimori is a 38-year-old woman who has built a happy family life with her husband and son. However, her daily routine undergoes a drastic change when her husband leaves for an extended business trip. As loneliness and isolation creep into her life, Rimi spends more time alone—time that catches the attention of her son. Watching his mother in her vulnerable state, his feelings for her begin to grow stronger. The film portrays the gradual shift in their family dynamics and the emergence of forbidden emotions between mother and son.