Mashiro is a new member of the Shiro High School Men's Rhythmic Gymnastics Club. He is a first year high school student.

He has moved around Japan with his father who is a video photographer. He went to the same junior high school as Misato in Miyagi, where he began rhythmic gymnastics.

Mashiro has an innocent and capricious personality, but he has a natural talent for rhythmic gymnastics and has the ability to win junior competitions.

(Source: Official Site, translated)