Mild innuendos and sexual references throughout.
A character often gets mistaken for a girl and is forced to cross-dress for various reasons at several points in the show despite showing discomfort to the idea.
A character is shown wearing excessively revealing clothes through most of the series, though she is often scolded for it and it's intended for laughs.
Occasional references to pornography including depictions of characters reading porn magazines, though nothing graphic is shown.
Two characters are continually called perverts. One character is extremely sexual (fan service).
In an episode where all the students come up with call signs/nicknames for each other, one girl complains about her nickname being "Scrunchies and boobs."
A female character asks a male character how she looks in a tube top that exposes a lot of cleavage. The close up on her chest lasts a couple second. The male character is very pleased, though the female character doesn't understand why.
A female character has her cellphone hidden in her cleavage. She gasps in surprise when it rings and her breasts jiggle in a brief closeup.
A female teacher forcibly kissed a male student for a prolonged amount of time to get information out of him as he comedically freaks out.
While going through solo pictures of students, one character in a picture is running around nude. No graphics.
A character on an island goes nude to join his (female) classmates who are playing in the ocean. Nothing happens at all.
A character has an aversion to huge breasts.
One character gets shoved into a female's chest from "hugging". He says something along the lines of "Stop it! I can't breath because of your enormous ta tas"
In an episode, a boy kisses a girl to put her mind away from assassination. This lasts for about 40 seconds.
Teacher shows a photo of a naked male student. The tie covers the frontal part.
A female character try's to please a male to try to kill him, but the male changes her at quick speed. No changing was seen. And she tells the student,"He also had time to do the thing", nothing is referred or talked about it,and it gets dropped easily.
Nothing too bad other than one character having slight cleavage however she gets teased for this and soon enough wears no cleavage.