This series highlights the many twists and turns the various characters face during Koyomi’s senior year of high school. As a new semester begins and graduation approaches inexorably, he finds himself facing crucial decisions, both for his future and for the relationships he wishes to preserve. Yet, as troubling events unfold, the teenager mysteriously disappears.

Although there are still traces of the brief period he became a vampire, third-year high school student Koyomi Araragi is human again. He happens upon others with their own supernatural problems and finds that he can empathize. Koyomi becomes involved in their lives, seeking to help them and occasionally asking for advice from Meme Oshino, the homeless man who helped him become human again.

Set after the events of Bakemonogatari, one of the men who deceived Hitagi, Kaiki Deishu, returns to town to spread the incantation which cursed Nadeko before. Koyomi's sisters Karen and Tsukihi try to stop him.