Yuuri Wakasa is one of the main characters of the Gakkou Gurashi! series. She is a former student at Megurigaoka Private High School. As the big-sister figure, Yuuri is the president of the School Life Club, where she is more commonly referred to as "Rii (-san)". She keeps a detailed record of food, electricity, lessons, and other resources and activities. Yuuri is usually very calm and mature, and acts in a collected and proper manner. She also is quite serious, always looks after her comrades, and is not afraid to scold someone when they put themselves in danger pointlessly.