Nagisa Sagan

This volatile experimentalist, who appears much younger than she is, has created humans immune to physical pain. Her mysterious past and strange lifestyle have made her an isolated figure, though she found a bond with Nana. She harbors a complex, antagonistic relationship with Ritsu, masking deeper, unacknowledged feelings with outward hostility. A notable arc involves a wager with Ritsu concerning her older siblings, Yamato and Koya, against Ritsuka's Soubi.