At the age of ten, Chiyo Mihama is a prodigious child who finds it challenging to fit in with her high school peers, who are five years her senior. The group comprises of girls in her class, including Osaka, who has a peculiar worldview and lacks intelligence, the short-tempered Tomo, ambitious athlete Kagura, easily agitated Yomi, and the shy and animal-loving Sakaki. Together with their teacher, they encounter obstacles and create unforgettable memories while traversing through the high school journey.