help finding manga

bl manga abt a dormitory school where the seme is kind of the leader of the dorm/student president and uke is the new kid and then seme appointed uke as his “assistant/brother” thing where they’re supposed to help each other with school stuff or whatnot. and then seme fall in love, turned out actually kinda crazy and locked uke inside his room??? but later he let him out tho. i remember the first time they meet is inside the school church, seme is receiving a bj from someone else