The newly appointed homeroom teacher has a disease that will kill him if his penis goes limp! (According to him: It's an incurable disease). He's a total pervert teacher, but he seems to be a very good teacher and is well-trusted by the students. The students (especially the female students) are desperately trying to help the erection teacher by using all sorts of methods to keep his erection from going limp! But once he ejaculates, his penis goes limp, so all they can do is stop just before he ejaculates. And the girls are left in agony...