When Daisuke’s father remarries, he finds himself living under the same roof as his stunning new stepmother, Yuri. What begins as a standard family arrangement quickly spirals into a complex web of hidden desires and forbidden attraction. Daisuke struggles to watch his father share intimate moments with Yuri, feeling a growing sense of isolation and jealousy that threatens to tear his composure apart. The fear that his father will claim her completely, perhaps even starting a new family that leaves him behind, pushes Daisuke to a breaking point where he decides to take matters into his own hands.
Seizing the opportunity when his father leaves for work, Daisuke confronts Yuri with his intense, long-suppressed feelings. The encounter begins with a desperate display of affection as he showers her with kisses and explores every inch of her body, effectively blurring the lines of their domestic dynamic. Although Yuri initially attempts to resist the advances, her own hidden fondness for her stepson quickly takes over. She eventually surrenders to the temptation, allowing their secret relationship to blossom into a series of passionate, illicit encounters that occur whenever they are left alone in the house.
As their affair deepens, the consequences of their actions become increasingly complicated. Yuri eventually discovers she is pregnant, leading to a lingering uncertainty that haunts both of them. The ambiguity surrounding the paternity of the unborn child creates a tense atmosphere, as neither can be certain if the baby belongs to the father or the son. This gripping story explores the depths of taboo desire and the unpredictable nature of a household built on secrets, leaving viewers to wonder how long they can maintain their double life before the truth is finally revealed.