Sachi Nagoya, sole heir to the prestigious Tokai-region Nagoya financial group, occasionally reveals her sheltered upbringing through socially unaware remarks. Yet she balances this with a cool-headed realism. Spurred by a desire for independence from her family, she pursues a career as a professional bicycle racer with the Nagoya Bicycle Racetrack, representing her region's velodrome.

Her determined, competitive spirit marks a significant personal transformation within the cycling world. She trains rigorously with friends met through an online cycling fan community—Tsutsuji Kurume, Remu Tachikawa, Izumi Itō, Kumamoto Ai, Yahiko Miko, and Takamatsu Kinusa—preparing for the October entrance examination into competitive racing. Each friend's surname corresponds to a city housing a velodrome.

Sachi favors Nagoya specialties Hitsumabushi and Oni Manju, and her favorite location is the Nagoya City Science Museum. Her social connections prove motivational; during a visit to a hot spring inn owned by Izumi Itō's family, Sachi declared her ambition to build a name separate from the Nagoya Zaibatsu. Combined with encouragement from professional racer Tsutsuji Kurume, this helped sway Izumi towards competitive cycling.