Souichirou is a sheltered boy from a rich family, living in a quiet town outside of the city. Then one day, he discovered that his father had gone missing after a failed venture in an African diamond mine and left him penniless. Since his father had aided the acting school chairwoman Saki many times, she let Souichirou stay in the janitor’s room if he worked as the school custodian. With no other relatives to depend upon, he had no choice but to accept these humiliating conditions.

Ordered around daily by his former classmates, he wished to run away but was bound by his financial situation. That’s when Saki revealed to him that she likes SM and would like him to help her out. So begins his new school life of humble caretaker by day and new master by night.