Toya Saeki works in the planning department at Sunlight Beverage and competes on the company's corporate badminton team as a doubles player, partnering with Koki Takeda. He leverages his natural instantaneous power and intuitive playing style during matches. Toya has brown hair, brown eyes, and blood type O.

To reduce living expenses, he shares an apartment with his older brother, Sota Saeki, who is four years his senior. Toya attended high school with Mikoto Shiratori, giving him familiarity with Mikoto's playing style and foresight abilities, knowledge relevant when Mikoto later joins Sunlight Beverage.

His given name, "Toya" (橙也), incorporates the character for "orange" (橙) and "to be" (也). His surname, "Saeki" (佐伯), combines "help" or "aid" (佐) with "count," "earl," or "chief official" (伯). Born on April 3, Toya is 19 years old during the events of the series.