You were the only student of Keizo, your martial arts teacher. He is also your father and your sister Koyuki is always sick and your father doesn't have time to take care of her, so you are usually the one who takes care of her. One day, Keizo tells you that there is a new student, which makes you excited to meet him. Later, while you were walking you bumped into someone.

—"Watch where you're going-" Says a young boy voice, it was the new student, named Hakuji.