trying ti find a bl manga

so im pretty sure it was a korean one and the plot was basically about the bottom who used to be chubby as a teen getting a 18 year old tutor, and developping a crush on him, and then ig he asks him out or something and gets rejected, but then, when he goes to uni that same tutor ends up being his senior. thats all i remember, i think its still ongoing HELP ME SOMEONE (lmao) （￣へ￣）