The story centers on Koyomi Araragi, a third year high school student who has recently survived a vampire attack, and finds himself mixed up with all kinds of apparitions: gods, ghosts, myths, and spirits.

High school student Koyomi Araragi survived a vampire attack and can’t stop getting mixed up with all kinds of apparitions—but he’s about to face his biggest challenge yet: protecting his two little sisters! Karen and Tsukihi have a penchant for justice, and it’s up to Koyomi to keep them safe as they track down the cause of their apparitions.

Tsubasa and Hitagi discover that Koyomi has gone missing and has urged them in a text message not to look for him. However, in his absence, new dangerous apparitions begin to appear and target Tsubasa, and Nadeko who are left to try and deal with them on their own. Meanwhile, Koyomi Shinobu, and Mayoi are dealing with serious problems of their own.

During the month of October of his third year in high school, Koyomi Araragi is introduced to a transfer student named Ougi Oshino by his underclassman Kanbaru Suruga. Ougi tells Koyomi that she has something she wishes to consult with him. When she draws the map of Naoestu High School, she finds something peculiar on there. This discovery reveals a tale that wasn’t meant to be told, and this makes Koyomi’s high school life totally different. This is the story that brings to light “what” makes Koyomi Araragi. This is the story that reveals the “beginning” of everything.

After graduating from high school, the story of Koyomi Araragi came to an end. This time, it truly ended. However, the story of the girls who were saved by Araragi was not over. It is a prequel, or perhaps a sequel to their struggles in youth.