Birthdate: January 1st (Capricorn)
Blood type: B
Height: 140 cm
Grade: 5-A
Team Jersey Number: 12

Hiiragi wears a yellow hairpin on the left side of her hair in order to avoid confusion with her older twin-sister Tsubaki.

Hiiragi is one of the Takenaka Sisters, Natsuhi's little twin sisters. Even if the twins practice basketball with Natsuhi, he himself does not acknowledge their talent. The combination of the twins is so strong that draws their opponents into confusion. Due to the combination and the fact that they share the same personality and thoughts, they are nicknamed "TsubaHii", sharing the first parts of their names. Both she and her sister use the masculine Japanese pronoun for I, "Boku", to refer to themselves.