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.
(Source: Ansatsu Kyoushitsu Wikia)