Help me find this

So it's about a childhood friends yaoi, the seme has a weird family they teach their child to be a possesive person (gwanggong) but he didn't like it and at the graduation of highschool the seme say good bye to uke to go to abroad (he's building himself to be a gwang gong) idk it's kinda hazzy but all I remember is that they met again and he apply all the shit he learned on the uke and he admit to himself that being possesive is really through their family blood. If it remember correctly he is kinda neird the seme