Koyomi Shirakawa

Оригінальне ім’я: 白河暦

Koyomi is Jun'ichi's homeroom teacher, one of the faculty's science teachers, and Kotori's older sister. She is also a researcher at the Amakase Laboratory, and in charge of the Miharu android. In the Second Season, she is a new mother, and her strict composure rapidly crumbles when she talks about her baby.