Mukashi no Uwaki Aite no Ko ga Jitsu wa Watashi no Musuko no Doukyuusei de...

A married woman from a small town has a secret past: she once had an affair. Years later, she discovers that the child from that affair is now a classmate of her own son. The encounter reopens old wounds and stirs buried desires, forcing her to confront the consequences of her past choices.

As she tries to maintain her family life, the presence of her former lover's child threatens to unravel everything. Caught between guilt and temptation, she must navigate a dangerous situation that could destroy her marriage and her son's future.