It had only one volume and the uke was targeted by demons due to his energy so the seme is an assigned bodyguard to protect him. They need to share energies or something of that sort, and then they fall in love. The seme and uke both had darker coloured hair, I don't remember much but I've been looking for it for a while. Does someone know it?

This girl moves into a new high school and sits next to a black haired guy. And then his blond best friend also starts talking to her and he's a bit mean to her initially. Later we find out that the black haired guy has a crush on some older woman and he confesses to her and they end up dating I think? I think there was something about her dad marrying the black haired guys mom also but I'm not sure. I've been looking for it for so long, I want to know how it ended please help