Akai  

Akai-sensei, 赤井

Yamada and Kosudas homeroom teacher is 25 years old. She teaches P.E., and due to her busy schedule at school, she has not yet found a romantic partner. Her colleague, Mori, first became involved in their lives when she learned that Kosuda had openly declared his feelings for Yamada. As class representatives for the Sports Day, they were paired together. During Christmas time in the manga, Akai-senseis erogami version of herself listened to Yamadas problems and learned about her sexual issues firsthand.