In a house where parents are frequently absent, a younger sister-in-law named Yuki harbors a secret yearning for her elder brother Kenji. Their lives take a supernatural turn when a ghostly figure named Hiyori emerges from Kenji's closet one night. As childhood friends, the trio reunites, evoking mixed emotions in Yuki as she witnesses Kenji and Hiyori growing closer. Memories resurface from their past, where a toy ring exchange was left unfulfilled due to Hiyori's sudden departure. The trio's intertwined destinies slowly unravel, unveiling a poignant love story filled with unresolved feelings and bittersweet nostalgia.