Chisato Mera attends PK Academy as a supporting character frequently interacting with the protagonist, Saiki Kusuo. Her financially struggling background profoundly shapes her behavior and personality. She exhibits extreme gluttony and food obsession, fueled by constant hunger stemming from family poverty. This preoccupation frequently overrides social norms and personal connections. She holds a part-time waitress job but performs poorly; a notable incident sees her instantly devour Saiki's coffee jelly upon serving him at the cafe, demonstrating her inability to resist food even professionally. Her character evolves across the series. Initially portrayed as more tolerable and likable in the first season, she regresses into a one-note glutton by the second season. This culminates in impulsive, selfish actions around food, including stealing meals directly from friends. One infamous moment in the second season's seventh episode depicts her descending into a "primitive state" and taking food from others without permission. While she sometimes attempts amends or assists friends afterward, this typically occurs only after considerable social fallout. Despite these flaws, she sustains friendships within the PK Academy group, including Saiki. He occasionally aids her, such as providing a plane ticket to Okinawa—an act indirectly benefiting another character, Teruhashi Kokomi—indicating a level of mutual, albeit strained, camaraderie. Her appearance features auburn hair, red eyes, stands 1.60 meters tall, weighs 48 kilograms, and her birthday is April 15.