A high school orphan who has moved into his deceased parent house by himself, but not for long as each of his teachers recognises his slipping grades and decide to secretly move in with him, becoming his "Mothers".

In the beginning of the series, it is shown that Hitotose is very good at fighting, as seen when he beats up two guys who were making fun of him because he has no parents; later on, in Happy Lesson Advance, we see his ability to fight numerous times during his conflicts with Nagatsuki Kuron. Hitotose's true feelings are also revealed in Happy Lesson Advance.

He actually replaces Susumu Arisaka from the manga version.