Sanemi is a very aggressive, hot-blooded boy who is often pushy and quick to lash out. Sanemi is a tall, muscular and slender man with spiky white hair, large pale purple eyes and his face and body are covered with scars. He is a math teacher at kimetsu academy, who is known for his aggressive behavior, and strict teaching methods. Though, he is very kind to women, and his elders. He always keeps his collar open, because he feels stressed when it gets stuffy around his neck.