Akai

赤井

The 25-year-old homeroom teacher for Yamada and Kosuda. She also teaches P.E. and is typically so occupied with school duties that she has put off finding a boyfriend. Her colleague is the Home Economics teacher, Mori. She first became involved in Kosuda and Yamada's lives after hearing Kosuda boldly declare his affection for Yamada. She subsequently paired the two as class representatives for Sports Day. Around Christmas time in the manga, she offers to listen to Yamada's problems, learning firsthand how much of them involve sex.
Akai-sensei's erogami is a high school version of herself.

Spoiler