he bullied him till he fall for him xD
so the main guy has all underwaer dirty so he buys new one to put on in school but got chaught by ukain that took a picter of him without them and sexually harrased him to get his way with him by blackmail beacuse he has big fat crush and didint know how to get his attention - toxic af but the senpai falls for it and starts to falling for him just beacuse they are fisiclly close they end up in relationship and are happy i guess
Ore no Pants ga Hitojichi ni Torarete Imasu