Itsuki married into the Ayuhara family with her son Masaru. Her husband's son, Tetsuo, a university student, is not happy about her relationship, and even after six months, she still has not gotten used to it. Furthermore, she is now sexless with her husband, who used to make passionate advances every night during their affair before they were married. Meanwhile, Tetsuo finds out that Itsuki had been having an affair since before his ex-wife died, and he questions her. Wanting Masaru to not tell anyone, she allows herself to be violated by Tetsuo, endures a milk enema at the breakfast table, and at night when the family is asleep, straddles Tetsuo's huge dick and shakes her ripe ass. And Masaru is at the age where he is awakening to sex...