Reiji Saga is a second-year student at Takafuji Private Academy and president of the Wonder Festival Club, which focuses on figurine collecting. He attends classes alongside protagonist Yūki Ōjima. His club faces abolition under a policy by student council candidate Satsuki Shinonome, who targets non-essential clubs. This threat allies Reiji's club with the Food Research Club in a broader struggle for institutional survival.

Physically, Reiji stands 190 cm tall and weighs 80 kg, with red hair and opaque nerd glasses. A propeller accessory is affixed to the top of his head. Peers refer to him by the nickname "Garage."

As club president, Reiji coordinates figurine appreciation activities and related hobbies. His role gains prominence during the student council election narrative, where his club's existence becomes contested. His documented interactions center on institutional responsibilities and physical characteristics.