In the anime, Usagi addresses him as Motoki-oniisan and initially has a huge crush on him. He is also friends with Mamoru Chiba, who attends the same college, Azabu Institute of Technology. His girlfriend is Reika, an excellent science student. He has a younger sister named Unazuki, who is also friends with Usagi and the others.
In the manga, Motoki works part-time at both the Crown Game Center and the Crown Fruit Parlor. He goes to KO University. In the first arc of the manga, he recognizes the Senshi and discovers their true identities, but he promises to keep it a secret.
