Sora Niimi 新海天

Sora is Kakeru's younger sister and a first-year student.

She spends most of her spare time hanging out at the protagonist's apartment, often threatening to move in, and sometimes makes him treat her to dinner. She has a selfish side, but her dedication to her brother is undeniable. She enjoys teasing Miyako for her overly-serious demeanor, and also for her occasional slip-ups.

When Sora awakens to her powers, she begins cooperating with Miyako and her brother on the investigation.