Responses
it's a sequel and if you read the first one you'll understand http://www.mangago.me/read-manga/high_school_lullaby/
He doesn't want to love him because he is clearly toxic. I feel like the seme wants a clear understanding of the uke to accept him and open his heart and the uke to go therapy cause I feel like he got messed up growing up seeing that he ends up being a goody two shoes. But thats just my opinion (⌒▽⌒)
The one had someone he loved before, but that person didn't love him back. Though he treated him like he was dating him in a weird way, so his way to love is a bit messed up. While the guy he likes now clearly loves him back with saving him from the perverts or anyone touching him yet he doesn't want to love him. I wonder why.