Aki-Sensei (安芸先生 Aki-sensei) is a character in Washio Sumi is a Hero, being the girls' instructor and mentor in their Hero training.
Aki-sensei is strict and stern with her students, but is not disliked. She does have a talent for scaring some students into submission. Underneath, Aki-sensei is kind and willing to help.
- She does not like green peppers.
- Due to her last name, it is possible she is a descendant of Aki Masuzu, a character in Nogi Wakaba is a Hero.
- In the original novel, her name was never mentioned-she was referred to as simply the girls' teacher.
- She was never shown in the novels either, aside from a quick glance at the side of her during Gin's introduction art.