Dansou Shitara Mukashi Mitai ni Amaete mo Hazukashi Kunai yo ne, Onii-chan?

During the summer of their second year of high school, the narrator is asked for help by Kaede Kisaragi, a college girl and their first love. Iori Kisaragi, who is three years younger and had been like a little brother during their time in the countryside, will spend the summer in the city with them. Kaede requests that Iori be treated as a brother and mentions she will dress as a boy during the visit. Upon reuniting after three years, Iori still appears clearly female, but she believes she has successfully disguised herself as a boy, which surprises the narrator. The story follows this summer of youthful romantic comedy involving a childhood friend who is clearly interested in the narrator.