جو ایدوگاوا

Student council president. At sometimes, she acts like a bossy high-class lady, while at sometimes she behaves like a tsundere, who wants to defeat Sasami no matter what.

[Spoiler: Her body changes along with her personality during midnight (implied), which is why she acts always differently. She is also a member of Arabahki, and goes along their schemes and plans to destroy world using Amaterasu's power.]