Noticing the strange behavior of her son 'Yuki' who was about to take an exam, his mother 'Reiko' grew worried. One day, when Reiko returned home, she found Yuki acting suspiciously as he left the bedroom, and in the room, there were Reiko's underwear with Yuki's semen on them... Reiko decided to talk some sense into him and began to educate him about sex using her own body.
