Harimoto is a second-year student at Hiroshima Kureminami Technical School and a member of the Hiroshima Kureminami Tech Bicycle Club. His exact cycling type is unknown, other than that he is not a sprinter. He functions as a minor background character who appears on the third day of the 41st Summer Inter High. He's left behind after Arakita, Onoda, and Manami catch up to Hiroshima after breaking away from the pack, exhausting himself from pulling as he's not a sprinter.
He refers to Machimiya Eikichi as "Eikichi-san".
In the anime, Harimoto appears with dark, tanned skin and white hair pulled back by a pink hairband in a similar hairstyle to Satozaki, with thick, white eyebrows. He has a mole under his right eye.
- His name was not revealed until the second season of the anime, Grande Road, where it appeared in the ending credits.