Keep It A Secret (FUNABORI Nariaki)

It is not everyday a high shool boy finds a girl masturbating to an erotic novel in school, but that's exactly what happened to Misato. However, being a decent person, when a teacher catches him reading the novel Kazumi dropped when she ran away, he covers for her by taking the blame. In spite of that however, Kazumi's fantasies prevail over common sense, and she forces Misato to take her as his sex slave to ensure his silence. With Kazumi's lust and masochism unleashed, Misato will have to embrace his sadistic side to contain his new meat toilet's overflowing desires.