I can't call you my stepmother... ~The body of my stepmother and my son, wet with lust~

Nana is her wife who married her mentor when she was a student. It was supposed to be a happy married life with her loved one, but she was spending awkward life without arching with her husband's stepchild, Shinya. That's right, Shinya was Nana's private tutor and had been in love at the time. Shinya is irritated by Nana, who keeps her distance as her stepmother, and forcefully plays with her plump body. If Shinya could recover by being victimized, Nana accepts the distorted inferiority complex and desires that have been shattered by his wishes...