Gender: Age: Birthdate: Sign: Height: Weight: Hair Color: Eye Color: Blood type:
Keiko Matsuda - Sister
Chapter 3 (mentioned)
- Sosuke Matsuda
At some point before the start of the story, Keiko was taken out of the country. It is unclear whether or not Sosuke was also relocated along with his sister or remained in Japan. He currently works as a teacher at Bura Bura Academy.
Keiko's older brother, who is a teacher at Bura Bura Academy and helped her enroll in her third high school year. It is unknown what he teaches at Bura Bura or what his relationship is with his sister.
Sosuke helps Keiko enroll in Bura Bura to keep her promise to Shiro despite the school's three-year rule. But after Keiko is caught sneaking around the faculty room she wonders whether Sosuke would be the one to pick her up and states that he deserves all the trouble she's putting him through. Implying the sibling may have a rocky relationship.