Fukutarō Yasunaga is a teacher at the high school where Tokiwa Kitareri!! takes place. He is the homeroom teacher of the class Tokiwa, Makina, Kanata, Meguru, Haruka, and Aria attend.
- He looks and behaves exactly like Fukujirō Yasunaga from History's Strongest Disciple Kenichi. The two teachers might likely be brothers.