Kaori Izumi is part of the assault squad in the Best Student Council.
Kaori is a strong and determined individual. She's seen repeatedly trying to impress the object of her affections, Kanade Jinguuji; and repeatedly daydreams about moments where she can spend time with the same. She also takes care of her younger siblings due to the passing of her parents. She is friends with nearly every member of the Best Student Council, but is fiercely loyal to its President. When they first meet, she's jealous of Rino Rando as the latter spends a lot of time with Kanade. As the school year progresses though, she develops a slow friendship with Rino, presumably after she comes to understand they are not so different.
Kaori is characterized as extremely individualistic (seen numerous times doing missions by herself) and a good student. Supporting her family, being a member of the Assault Squad and Best Student Council takes up most of her time. She's extremely touched when her "secret" comes to light and the other members of Miyagami Academy's governing body take shifts babysitting her younger siblings while she's working.