After several years of marriage, Ryo Ko finally had a child, her beloved son Kenji, and the family lived together in happiness. Their peaceful life as a trio—energetic Kenji obsessed with soccer, a kind and gentle husband, and devoted mother Ryo Ko—seemed like the perfect family. But one day, everything changed when her son accidentally saw her naked after a bath. From that moment on, Kenji began seeing his mother as a woman, and his suppressed desires eventually reached their limit. Unable to hold back any longer, he forcefully pushed her down. Though she resists at first, Ryo Ko ultimately yields to her own son. What unfolds from this forbidden choice is a new life filled with taboo, desire, and overwhelming guilt.