Kazuharu is a sleazy pervert, openly sexually harassing any chance he gets. He has a strong attraction for the girls that hang around Yukinari, and will do anything to take them away from him, for some little sex games that is. That aside, he has a tendency to appear (often out of nowhere) and attempt to manipulate the situation to his own advantage. Aside from all that he has a close relationship with Tomoka, as he is often called her big brother.
He is also incredibly rich, living in a ridiculous mansion with his sister and all-female employees.
Another strange thing about him is that he breaks out in rashes when he gets close to men, making him the antithesis to Yukinari.