A further tightening of the screws, and maybe the first step in the next direction for this story.
Third installment in this symphony of adolescent emotional brutality pits hapless would-be seeker of transgression Kasuga against his (female) mentor in perversity Nakamura, with his would-be sweetheart Nanako caught between them. After Kasuga and Nakamura enjoy — not sure that's really the word, actually — an orgy of destruction in their school homeroom, Nanako's forced to see what Nakamura wants her to think the "pervert" Kasuga is really made of ... except that Nanako is even more pure-hearted than anyone banked on her being. Where the story goes from here ought to be a real challenge; let's see if they branch out even further and more daringly, or simply repeat the same beats as per a goofy sitcom where nobody ever learns. My money's on the former.