After meeting oddity specialist Izuko Gaen, third-year high school student Koyomi Araragi awakens in a bizarre, empty void, where he is greeted by a delightfully familiar face in a shockingly unfamiliar setting. With the assistance of his girlfriend Hitagi Senjougahara, Araragi navigates the threads of his past and the confusions of the present to find answers. Yet, fate once again leads him to the eccentric transfer student Ougi Oshino, who presents an unexpected proposal that might expose the very foundation he is tied to. As Araragi uncovers the layers of mystery surrounding a phantom, he finds a truth that was never intended to be revealed.