After a fight with her husband, Jun's mother's best friend Ayano runs away from home, so Jun has to hide her in his house for a while. Jun is still in his teens and is excited to be living with Ayano, who exudes sexiness that makes it hard to believe she is just his mother and classmate. As if she can see through his ulterior motives, Ayano keeps giving him provocative panty shots and breast shots... Jun can't help but lock himself in his room and masturbate while thinking of Ayano, but Ayano sees him doing so...!?