Oka Hiromi, a freshman at Nishi High, joins the school's prestigious tennis club because of her admiration for Madame Butterfly. Despite her clumsiness, Coach Munakata recognizes her potential and chooses her for the next competition. Hiromi's unexpected promotion earns her the disapproval of her fellow tennis club members. But with the support of student council president Toudou Takayuki, she begins a rigorous training program under Coach Munakata.