I know I'm not the only one that had thought of sensei with a killing intent even for once. But I kinda remember reading from another manga in this series that he sort of got a special person with black hair(it was a picture or a memory). I guess he's heart broken or something. Honestly I feel bad for him. Hopes he regrets his cowardly and pitiful actions.
Keum Myuong-wi. I've never memorized a name like this before. But I need it so I could write his name on my death note. And many others.