Kyouka Izumi

Kyouka Izumi is Masamune's aunt and the younger sister of his father, Kotetsu.

Background
After the death of their father, Kyouka assumed guardianship of both Masamune and Sagiri.

In the sixth episode, Masamune mentions that he originally had made an agreement with Kyouka to let him and Saigiri continue living in the house by themselves, so long as he is able to continually show results as an author.

Relationships

 * Izumi Kotetsu - Brother (Deceased)
 * Izumi Masamune - Nephew
 * Izumi Sagiri - Step-Niece