Kaori, the new stepmother, is only slightly older than her stepson Takashi and his siblings, which feels strange yet thrilling to him. With her stunning figure—especially her voluptuous hips—she becomes an irresistible presence. Takashi finds himself constantly staring at her back and buttocks, whether she's doing housework or sleeping. He fantasizes about smearing oil on her skin, rubbing his cock against her body, and pleasuring himself with her ass. But these fantasies are no longer enough. Gradually, his feelings for the real Kaori deepen, blurring the line between desire and reality.