A-Channel centers on the everyday lives of four high school girls whose friendship is shaped by contrasting personalities and a tightly knit routine. Forgetful and good-natured Run Momoki has been best friends with Tooru Ichii since childhood. Although Run is one year older, her carefree attitude and popularity with the boys are a constant headache for the fiercely overprotective Tooru, who applies to the same high school so they can stay close.
By the time Tooru arrives, however, their longtime circle of two has already expanded into a quartet. Run's classmates Yuuko Nishi and Nagisa Tennouji are now part of her daily life, and in Tooru's eyes both girls must prove that they are trustworthy. As a new school year begins, Run, Tooru, Yuuko, and Nagisa balance their friendship with the exhilarating opportunities of school life, turning ordinary days at school into a portrait of a group that keeps growing even as Tooru tries to hold on to the bond she treasures most.
