Fifteen-year-old Hiyori Nishiyama is involved in an accident the day before her high school entrance ceremony, resulting in hospitalization for severe bone fractures that stunt her growth. Because of her shy disposition, she remains hesitant to attend classes even after her recovery. However, when Hiyori finally chooses to return to school after a year, the situation takes an unexpected turn. As she attempts to introduce herself, she is suddenly cut off by Yuushin Hirose, a tall and extroverted boy. Hiyori not only misses the opportunity to make a favorable first impression on her peers, but Yuushin also mocks her by likening her to a baby bird. Nevertheless, thanks to Yuushin's outgoing personality, she gradually becomes more comfortable with her classmates. With Yuushin by her side, Hiyori hopes to achieve her aim of making friends.