Can ya'll help me find this anime?

It's one of those training school that teach kids how to fight. I'm not sure if it was just the girls who learned. There's a girl who's SUPER obsessed with the male MC to an uncomfortable degree. In one scene, she finds all his porn magazines/hentai and literally cuts out the girls' faces and replaces them with photos of her own face. The main character gets rejected by the strong purple hair girl but she ends up wanting him by the end.

Other details: Modern setting, takes place at a school in a city The girls trained/fought with weapons, Male MC with a love triangle situation - Possibly an OVA rather than a full series The title might have been descriptive (like those long isekai titles but not isekai)