The Hiiragi family is Kagami and Tsukasa's family. It is the largest family of the series, consisting of six members, including the parents and four daughters.
It consists of:
- Tadao Hiiragi - The father and only male in the family
- Miki Hiiragi - The mother
- Inori Hiiragi - The eldest sister of the family
- Matsuri Hiiragi - The middle sister
- Kagami Hiiragi - The older twin
- Tsukasa Hiiragi - The younger twin and youngest in the family
- Due to the anime's popularity, the Hiiragi family has been officially registered as residents of Washimiya.