Ai Momoi

She and her sister are oldest of the twins appearing in the series. Ai is the teacher responsible for Nozomu's, Kira's, Yura's and Keisuke's class, Class 3-1. Ai is the youngest twin. Ai is also an Economics teacher. Ai appeared in Episode 01 - The Town with the Twins' Grave.

She is voiced by Chiaki Takahashi.