A widow named Makiko Miyashita begins a relationship with a young man she met on a dating site. However, she is shocked to discover that the young man is actually her late husband's son. Conflicted yet intrigued, Makiko finds herself drawn to the way her stepson callously toys with her body, treating her like his real mother. Their twisted interactions deepen their bond in increasingly perverse ways. Caught in a whirlwind of emotions, Makiko is forced to confront her own desires.