Hakuto Kageyama, a high school student, deliberately plays the role of a background character while indulging in his favourite past time: watching other people’s youthful lives unfold for his entertainment. Having no interest in experiencing his own youth, he is fine with remaining just an observer – until everything changes when his beautiful childhood friend, Sara Ginjou, transfers into his school. Sara, whose carefree personality once saved him, has—surprisingly—become a socially awkward loner who fears and rejects others due to a traumatic experience in middle school! Yet she still opens up to Hakuto alone, affectionately calling him “Haku-chan”. Determined to give the sweet and steadfast Sara the best high school life possible, Hakuto gives up his role as a mere viewer and begins pulling strings from the shadows to help her enjoy the best high school life possible!