Takeshi is trapped in a secret, illicit relationship with the sexually aggressive Fujino-san, struggling with guilt as he helps care for the young Shinobu. While navigating the tension of Fujino's nymphomania and the strained family dynamics, Takeshi's precarious situation reaches a breaking point when Fujino's estranged daughter, Fumino, unexpectedly returns home and catches them in the act.
Takeshi becomes entangled in a complex web of desire and trauma involving Fumi-nee, Fujino-san, and Shinobu. After grappling with the dysfunctional dynamics and emotional scars of the household, Takeshi attempts to leave to force a reconciliation between mother and daughter. However, through passion and mutual understanding, the four eventually forge an unconventional bond, choosing to live together as a happy, albeit twisted, family.