Haruki Hishida is a supporting character in the anime series Rideback. He is a student and serves as the primary mechanic for the university's Rideback club, where his technical expertise is essential for maintaining and adjusting the machines. His role is crucial behind the scenes, as he is the person who fixes, tunes, and keeps the team's ridebacks in working order. Beyond his mechanical duties, he also helps manage the school club dedicated to Rideback riding. In terms of his studies, he is a second-year English student. Physically, Haruki is an adult male with brown eyes and brown hair that reaches his neck. He typically dresses casually in shirts, jeans, and sneakers, and he wears glasses.

In personality, Haruki is depicted as a smart and witty individual. His key motivations are rooted in his passion for Ridebacks, which drives him to support the club and its members. He is a key figure in the life of the protagonist, Rin Ogata, as he is the one who introduces her to the world of Ridebacks. On a rainy day, he mistakes her for a prospective club member and eagerly lets her try out a unique machine called the Fuego, showing her how to operate it. From the very beginning, he is portrayed as helpful and enthusiastic about sharing his interest in the vehicles. Throughout the series, Haruki fulfills the role of the supportive friend and club manager. His relationship with Rin is central to his function in the story, as he witnesses her incredible, ballet-inspired riding skills with utter disbelief and amazement. He also works closely with fellow club member Tamayo Kataoka, as together they form a team for which Haruki acts as the mechanic.

Regarding his development, the character serves as an observer and commentator on Rin's journey. He is part of a key conversation with Rin's friend Suzuri Uchida, during which Suzuri expresses that she would rather see Rin dance on a stage than on a Rideback. This discussion with Haruki highlights a central theme of the show, focusing on Rin's search for a new purpose after leaving ballet. Haruki's notable abilities lie not in piloting, but in his technical and mechanical skills. He is the club's go-to expert for repairing and adjusting the sophisticated robotic motorcycles known as Ridebacks, ensuring that the machines are ready for the club's activities and for Rin's remarkable performances.