Systems engineer Kotarou returns to the old family home in Hachioji with almost no memories of his childhood before he was orphaned. One memory does survive: Hime, a winged girl he eventually dismissed as an imaginary friend. Back in Hachioji he discovers Hime is real, a tengu who remembers him clearly and announces that they are going to marry. Kotarou’s practical adult life is abruptly interrupted by a supernatural relationship rooted in a childhood he barely remembers.