To Protagonist Kousaka Shinichi, there was a secret that was not able to be said to the unrelated person. With Mizuho who is his mother, it is in the relation of men and women. Officially, though it is assumed it is parent and child, that relations are good and treats, two that have mutually continued forbiden relation of loving. Happy life of mother and child, it is suddenly destroyed by a man of alone.

Man's name is OnizawaShigehiko. It marks down to the pretty face of Mizuho before, it was an uncouth man who had frequently been visiting original of mother and child. Onizawa that knows mother and child's secret, the sexual relations is demanded from Mizuho as terms that do not make it public. To protect life with the son who loves, Mizuho that will give oneself completely to Onizawa. She will get the ripe body developed before long with the hand of Onizawa, it becomes the prisoner of pleasure...