She is one of Nagisa's classmates and close friends, being the one who is mostly seen with him. She hasn't shown any capabilities during her training to become an assassin, and so far has only been shown to discuss Korosensei's weaknesses along with Nagisa. She experiences a slight inferiority complex when it comes to sex appeal, resulting her to get angry whenever there's a woman with big breasts and readily protest.

Spoiler

it's revealed later in the story that she's Aguri Yukimura's younger sister, Akari Yukimura and her real birthday is on November 9.