I'm sorry but hoshino or whatever his name is, is the bad person in this story. He is the outside person who purposefully inserted himself into something that was already a situation and then he made it an even bigger situation by using manipulation and taking advantage of those ho were in pain. The worst part is that his feeling weren't even real he just wanted something cause he couldn't have it and that's it. This was a big damn game to him. Playing with people's lives.
Kimi No Kao Ni Sasu Kage