Katou is one-third of Komi's first-year field trip group. She and Sasaki Ayami make a pact to make sure the trip is as fun as possible for Komi. Katou makes a schedule for the trip but things don't go as planned leading to her getting in a minor fight with Sasaki but Komi ends it quickly. Later on in the manga, Katou teaches Tadano and Komi shogi strategies. Katou has black hair that is tied in circular braids on each side of her head. She wears circular shaped glasses and is most often seen wearing the Itan school uniform.