Momoko, a mother whose husband passed away three years ago, has been raising her son Kazuya harshly by herself. - However, her grades in studying never improved, and she became increasingly frustrated due to the stress of education. - She can't hold back the vibrator she confiscated from her son's friend, Shunsuke, and ends up masturbating. - Shunsuke happened to witness it... - Momoko's sexual desire went out of control from masturbation, and instead of scolding him, she grabbed his erect penis and started squeezing it wistfully...