Sora Kashiwagi is related to Miss Kobayashi
- Both have red hair
- Both sound similar to each other (because they are both voiced by Mutsumi Tamura)
- Both have experience with fantasy creatures living in their home.
- Both go against stereotypical gender roles (Kobayashi dresses androgynously, is often mistaken for a guy, etc. while Sora does cooking and other household chores and is often described by others as girly).
We are never introduced to Sora's mother, and Sora's Aunt has white hair, so it is very likely that his mother had red hair. It could be that Kobayashi is his cousin or something through Sora's mother. We have never seen Kobayashi's parents, so that leaves this open to speculation.
