Satoshi failed the university entrance exam and is retaking the exam. Worried, his parents ask a tutor they know, Mitsuyo, to help Satoshi with his studies. However, Satoshi is distracted by Mitsuyo's overly voluptuous bust and cannot concentrate on his studies. Mitsuyo tells Satoshi that if he studies hard, Ito touch her breasts as much as he likes. Satoshi is suddenly motivated, but his demands escalate...