Nanami Io

A jinyou living in Kamizawa city, and the student council accountant of the academy there. Very temperamental but intelligent. An ideal type to be a committee chairman. Her father is the director of the local hospital, and her mother works there as a doctor. Nanami too aspires to become a doctor (or maybe a Soba shop owner's wife).
She originates from a youkai called Shichinin-Misaki, and thus she's able to think in multiple parallel ways at the same time using her ability (she stops at three though given that she gets anemic upon trying more).
Childhood friends with Uesugi Keijirou, they both seem to be aware that the other might feel more, but they are in a state where neither steps in to change this.