アイ

When Ryou just got to the school, he saw Ai in front of his class, so he thought she was a classmate and tried to start a conversation with her. However, Ai screamed and ran away. However, from time to time, she shows up and sees Ryou in unexpected and embarrassing situations.

She's the school principal's, Taiga's daughter. Yukari infuriated her and when Ai tried to attack her, Yukari dodged, causing Ai to hit her head. Because Yukari convinced Taiga to not fuss over it, as it would make a scandal, the medical treatment was late, resulting in irreversible damage to Ai's brain. Ai has been in a coma for ten years already. What Ryou sees and talks to is actually her spirit which left her body./

Future: She's not mentioned in the prologue's future.