Miyuki strives to be the best mother she can for her son, Yutaka, attempting daily to serve as a shining example of a good mom. Yutaka has a friend named Masato, who holds a different idea of a good mom in his head, and one day makes a move on her... He takes her at home in the kitchen, in the bathroom, and even while her son is sleeping right next to them, claiming her as his own... Until one day, she is bound and blindfolded, and once her blindfold is removed, she is shocked to see that it is her son having sex with her! What kind of horrible mother has she become...?