Saki Kyūbu

Saki Kyūbu (久武 早紀) is the younger step sister of Seiya Kanie.

Background
Saki was the daughter of Seiya Kanie's father, Kyubu Takaharu’s, second wife. Through her father, she is Seiya Kanie's younger step sister, and the step niece of Aisu Kyūbu, her step father's sister.

Seiya Kanie
Seiya is Saki's step brother who has a friendly sibling relationship. Seiya lived with Saki for a short time before leaving to live with his aunt, Aisu Kyūbu. Despite this the two still meet on a regular basis.

Aisu Kyūbu
Aisu is the sister of Saki's father, making her Saki's aunt. It is unknown what they think of one of another as they have not been seen interacting with one another.

Etymology

 * The name Saki means "already, now, early" (早) (sa) and "hope" (紀) (ki).
 * Saki's surname Kyūbu means "long time" (久) ( kyū ) and "military, martial" (武) ( bu ).