When her husband's relatives and their husband died in an accident, Toko's family decided to look after their son, Yuta. However, Toko was unaware of the secret lust that Yuta had been harboring towards Toko for a long time... Having fulfilled his wish to live with Toko, Yuta begins to depend on her as if she were his own son. When they take a bath, he reaches out to her lower body, earning his son's resentment. His Kokoro is ignited and he offers his hardened crotch to Toko, and the sexually frustrated Toko accepts, even going so far as to have sex with him, ignoring her husband. Toko lets her guard down, thinking he's just a little kid, but before she knows it, she's shaking her hips violently on top of him...