Sanemi Shinazugawa, twenty-one year old math teacher. Tall man of very muscular build, spiky white hair and almond-shaped eyes with purple irises. Has dark patches beneath his eyes, making him appear perpetually tired or restless. Older brother of a fifteen year old student named Genya Shinazugawa. Oldest of six siblings. Abrasive, hot-blooded, rash, and stubborn, often times impulsive and quick to lash out.