What a wholly irredeemable character the teacher turned out to be. Crushes on, stalks, and starts dating a child, knowing he comes from an unhealthy home, causes him no end of grief trying to keep her happy, not to mention making things super awkward for Mikuni, and then dumps him for the one thing that a kid in his situation is least likely to have: normalcy. If he didn't have four girls lined up to suck his dick in the aftermath Keita could've easily come out of this relationship scarred for life.