Also known as: 古関ウイ, 코제키우이, 古关忧, 古関, ウイ
A character from Blue Archive. Chairman of the Library Committee. Her full name is Kozeki Ui.
Ui has a tied and very long Black Hair and very dark Blue Eyes with a sullen look that complement her personality. She wears a black Turtleneck Sweater under her white Trinity school uniform that comprises of White Shirt, White Sailor Collar with light gold trim, white Long Skirt, Purple Neckerchief, and a Brown Cardigan on the outside. She also wears a large Brown Slippers.
Her firearm of choice is the De Lisle Carbine.
Voiced by: Gotou Saori
Original artist: CHILD (Isoliya)