Aguri Yukimura is the former teacher of Class 3-E and the late older sister of Akari Yukimura.
Aguri is shown to be cheerful, clear-minded, and passionate when it comes to teaching. As a teacher of Class 3-E she is quite intelligent, being able to teach any subject in spite of chemistry being her first preference. She is known for her odd sense of fashion which often leaves others dumbfounded.
Aguri was the older sister of young acting prodigy, Akari Yukimura. Prior to the start of the series, Aguri held two jobs: one working as the teacher of Kunugigaoka Junior High School's Class 3-E during the day, and the other as the lab assistant for her fiance, Kotarou Yanagisawa. One day, she was assigned to be the caretaker of the recently captured master assassin, the God of Death, as none of the other lab assistants were willing to approach the assassin and she was treated as expendable or a "sacrificial lamb" as noted by Yanagisawa.
Originally Aguri was meant to be his means of escape, but after saving her from Yanagisawa the God of Death befriended her and the two became close as the year went on. Aguri shared her troubles with him and kept him company and he helped her improve her teaching methods. When the order to kill the God of Death reached her ears, she decided to warn him of the impending danger and decided to help him escape. Despite this, he didn't listen and was about to use his newfound power to break himself out of the prison. She then tried to convince Yanagisawa to help the God of Death but instead met with a beating from her enraged superior. As the building around her was being demolished by the now-omnipotent assassin, she witnessed her colleagues around her being killed by him and as a last resort to calm him down, she hugged the assassin from behind. However, she caught in the fire of the weapon set up by Yanagisawa and was mortally wounded.
Because her wound was too severe to be healed, she used her last breath to convince the God of Death to not become a killing machine, instead advising him to become a teacher, continuing her teachings and to never let the students go.
