Touko has entered into a relationship with her student, Tanaka. It's a secret between the two of them. She must do whatever it takes to make sure it doesn't get out. However, it seems that Touko is the only one who thinks this way, as Tanaka, a young man with a brimming with Kokoro, gradually begins to make advances at school as well... In the classroom during class, in the staff room, in the nurse's office... Tanaka is into her everywhere in the school, even if there are other people around, and Touko is worried that he might find out at any moment... but the thrill becomes addictive...