Read 1-Nen A-Gumi No Monster manga
It’s rumored that Class 1-A of a certain all-girls high school is hell itself, with every teacher quitting in a matter of days after being subjected to the girls’ abuse. Ultra-plain Jimi Taro (his name literally sounds like the Japanese word for “boring/plain”) is the latest teacher for this class but is unfazed about the challenge he’s up against.
Cute teenage model Hananaka Momo is the first to try and get him to quit, going so far as to fake a sexual harassment! Meanwhile, blackmailers, sadists and more lurk in this classroom of pretty faces, ready to challenge their new teacher. But Jimi’s motto is “virgin for life, teacher for life,” and he’s prepared to school these girls in more ways than one!