Mariko Kumakura, known as Mari, excels academically but struggles with social connections due to her reserved nature. Akiko Oohashi, a popular and extroverted girl, sets out to befriend Mari with her unwavering positivity. Alongside Akko's friends—easygoing Satoko Sugiyama and lively Tamami Sekine—the group navigates the challenges of adolescence and the complexities of teenage life. As Mari and Akko become closer, their bond deepens, sparking questions about the nature of their feelings and the evolving dynamics of their friendship.