tl;dr is awkward kid tried to talk to his childhood crush, but others mistook his intention (other kids, the girl, makoto...well, makoto is more of "I don't know or care") to be bullying the girl who's a noble that 'abandoned her people to run away'
After this he keep trying to contact her, hoping to sort things out, but since Makoto order his people to prevent him from getting close to her the kid could never do so and the misunderstanding never solved.
He eventually get manipulated by the demons and turned into a monster and get killed.
Though a glimpse into an alternate reality where Makoto never come to this town show that he will get turned anyway since the demon plans doesn't involve Makoto but eventually regain his sense and join Hibiki...only to get microwave'd by that timeline's crazed Makoto....'egg in a microwave'....