Kiyotaka had experienced a swap encounter involving his mother Eriko, his aunt, and his cousin, and his mind was deeply shaken by the pleasure he felt. The incident left a lasting impression on him, impossible to forget. Even though his mother said, "Let's just forget what happened today," Kiyotaka couldn't erase the ecstasy from his mind and was driven by forbidden desires. Faced with her son, now lost to reason, Eriko finds herself surrendering to illicit pleasure, desperately suppressing her moans as she gives in beside her husband.