Mashiro Arisaka is a first-year student at Kunahama Academy and a main character in the story. She has a petite stature, standing at about 148 centimeters, with long blonde hair usually tied in twintails and light purple eyes. Her birthday is February 14. An enthusiastic and lively personality defines her, and she tends to express her feelings openly, though she may occasionally display childlike behavior. She is also an avid gamer and has interests typical of an otaku.

Her deepest motivation stems from her profound admiration for the older student Misaki Tobisawa. This admiration began when Misaki approached her while she was eating alone, and they formed a close friendship. Mashiro’s devotion leads her to follow Misaki often, and she joins the Flying Circus club at the school primarily to stay close to her. Despite her small build, she possesses notable tenacity and develops into a skilled speed-type player in the sport, demonstrating single-minded dedication in training and competition.

Within the story, Mashiro is a member of the newly formed Flying Circus team coached by Masaya Hinata, alongside Asuka Kurashina, Misaki Tobisawa, and the Aoyagi siblings. Her key relationship is with Misaki, whom she regards almost as a princess; however, she also bonds with the other team members over time. Her character development involves learning to balance her near-obsessive admiration for Misaki with her own personal growth and aspirations in the sport. Her family background includes her mother, Botan Arisaka, who runs a local udon restaurant and provides a supportive home environment. Mashiro’s notable ability on the field is her speed, which makes her a formidable opponent in flying circus matches.