- This page contains Yuriko's relations to other known characters.
- Not much is known about the relation between Natsumi and Akari, other that they were friends.
- Not much is known about the relation between Natsumi and Hibiki, other than they were friends.
- Not much is known about the relation between Natsumi and Hibiki, other than they were friends.
- Not much is known about the relation between Natsumi and Kazumi, other than they were friends.
- Not much is known about the relation between Natsumi and Misora, other than they were friends.
- Not much is known about the relation between Natsumi and Reon, other than they were friends.
『Ryuu Hinata』
- Natsumi is a younger twin sister of Ryuu. She would have panic attacks and would normally ask her brother to protect her.