Takuhiro is a student who doesn't care, and pretty much gropes every good looking female student he passes. During the morning call through the speaker, he is send to the principle's office before class even starts. Here he is deemed inapproperiate an dgets punished by being send to the school's underground section where he becomes part of one of the 'naughty male behavior classes'.
this underground section looks like a medival prison, contains sawed through pipes in the walls for some reason and generally smells off, causing the student to believe its a sewage, not a floor (even though the floor is clean, etc.)
His new class. class oddly enough contains a lot of good looking girls who moan for some reason and most prominently a sexy teacher. The instance immediately works on his libido.
The teacher claims the class starts and people need to sit down. Takuhiro, asks what the class is. The teacher's eyes fal on the newcommer and licks her lips. He then realizes her eyes are aimed at his crotch. Feeling exposed he tries to gard himself from the stare with his hands, but seemingly that move turned on some of his classmates.
Scared he walks back, but then he realizes that is odd, and tries to convince himself its okay. (he wants sex basically)
The teacher assigns one female student to assist him. Then some ntfw scene happens, where the character is undressed, and the girl helps herself undress, the teacher uses her whip to (punish) increase the excitement of Takuhiro. There is some tonging between the two students. Takuhiro realizes he felt a girl more closer than ever before and before he could realize he was turnedinto one during the sex stuff. After that he can't help but to finger and grope himself, saying its a dream and such.
Once all students are turned, real class begins, but Takuhiro at least can't stop fingering and is relieved from the correctional class for now.
In the mean time he hears that the first period is P.E. with another teacher.