It seems that his mother, Ayano, is cheating on him... As a son, Kosuke cannot forgive his mother's infidelity and decides to punish Ayano. The way to do this is to train her by breaking her penis. When Kosuke finds out that Ayano, who he had always seen as a mother, is actually a lewd woman, a twisted desire begins to grow within him. He attacks her while she sleeps, restrains her, and takes away her freedom, then he gives her a deep throat blowjob, chokes her, and inserts his penis into her. Ayano succumbs to Kosuke's thorough training play and forced creampie, and is forced into a humiliating relationship of master and servant with her son.