Tooru frequently visited Akira's house and had developed romantic feelings for Akira's mother, Yuki. One day, Tooru accidentally witnessed Yuki secretly masturbating in her room. Overcome with excitement by her lewd appearance, his uncontrollable desire eventually drove him to approach Yuki, leading to them becoming intimately involved. This encounter escalated further when Tooru invited another friend over, pressuring Yuki into a threesome.