Nadeko comes to thank Koyomi, and the two geek out over a shared interest. Tsubasa Hanekawa passes by and suddenly complains of an acute headache.

Koyomi is over the moon when Hitagi announces their first date will finally happen. But on the day of, he finds that she is not the only one there.

Koyomi takes Tsubasa on a visit to Meme to find out how to save her. For some reason, Meme is acting indecisively.

The five girls' problems with supernatural beings have been solved, and it's now summer break, with the culture fair over. Koyomi Araragi has two little sisters, self-proclaimed "heroes" nicknamed the Fire Sisters, Karen and Tsukihi.

Araragi leaves Kanbaru's house and meets a dangerous man named Kaiki. While following him, he runs into Senjougahara, who berates him for skipping his studies.

Karen is acting clingy and very cute, completely out of character. But its a trick to get Koyomi to introduce her to Kanbaru. In response, he devises a test Karen must pass; a test involving her toothbrush.

Araragi, initially ignoring Oshino's warning not to involve himself any further in this incident, visits Hanekawa's house and is shocked by what he finds. He returns home and convinces his sisters not to involve themselves in the Curse Cat incident either. A few days pass and Hanekawa is still nowhere to be found. Araragi returns to Oshino to find him severely injured from his numerous encounters with the Curse Cat. Later, Araragi manges to find and talk to the Curse Cat occupying Hanekawa. Calmer and less violent now, she tells him to leave her to her own devices in order to relieve her master's stress.

Araragi begs Shinobu for her help, which she eventually provides. He then formulates a plan to confront the Curse Cat and save Hanekawa.

The first day of the second trimester, Tsubasa Hanekawa chats with the ghost girl Mayoi Hachikuji en route to school. Right afterwards, she witnesses a giant “tiger” apparition. Later that day, her house completely burns down from a fire.

Tsubasa determined the identity of the giant tiger apparition “Kako,” and writes one long letter. The letter was addressed to Black Hanekawa, the apparition that could be described as her other personality.

A recap episode retalling the events of Nekomonogatari (Kuro), narrated by Koyomi. On the first day of Golden Week, Koyomi Araragi, together with Tsubasa Hanekawa, buries a tailless cat that was ran over by a car. A supposedly petty and commonplace event. However, the curtain rises on the “nine days of hell" that follow.

A recap episode retelling the events of Bakemonogatari from "Hitagi Crab" to Nadeko Snake", narrated by Koyomi. One day, Koyomi Araragi caught the body of his classmate Hitagi Senjyogahara, who was falling down after slipping on the stairs, knowing that it was dangerous to do so. However, her body was surprisingly light, as if the concept of weight did not exist.

A recap episode retalling the events of Bakemonogatari's Tsubasa Cat and the entirety of Nisemonogatari, narrated by Koyomi. During the summer vacation after all the apparition-related incidents around the five girls have been resolved, Koyomi Araragi's two risky younger sisters – the self-proclaimed heroes of justice, Karen and Tsukihi – become involved in some trouble.

Suruga realizes that the collector is in fact Rouka, and she has been collecting parts of the "devil" as she feeds off the misfortune of others. Her motives are questionable...

Upon finding the Demon's head, she meets Rouka once again. Instead of giving the head to Rouka, she refuses. She is unable to stand the sight of her because of the fact that she can see her as she is a ghost. Suruga then challenges Rouka to one-on-one basketball in a wager for the head if Suruga loses.

Koyomi and Yotsugi land at the base of the mountain, where they are surprisingly met by Ougi Oshino. She talks with Koyomi for a while about his current situation and his upcoming confrontation with Teori. Koyomi and Yotsugi begin their journey up the mountain.

Koyomi and Ougi find themselves trapped in a classroom, and the story shifts back to the point when Suruga introduces Ougi to Koyomi. Ougi approaches him with a mystery about a room not seen in the school's blueprints for them to investigate. When they enter the room, they find themselves trapped inside, leading them to their current situation. While talking about their predicament, the duo realize that the room is an oddity created by a traumatic memory from Koyomi's freshman years. Koyomi then tells Ougi that two years prior, the class president at his and Hitagi's class at the time, Sodachi Oikura, was looking for possible culprits of cheating on a math test, and would not allow any student to leave class until a culprit was found. Ougi surmises that they themselves won't be able to leave the room until the two-year-old mystery is solved.

Koyomi Araragi waits in the ruins of the cram school to ask Suruga Kanbaru for help, a request he hopes she will refuse.

When Koyomi asks Yozuru Kagenui about the extent of her relationship with Yotsugi, she challenges him to a fight. But then Yozuru disappears...

On Exam day, Koyomi visits the North White Snake shrine to look for Kozuru. Instead he sees Izuko Gaen there.

March 13th, the morning of college entrance exams. Koyomi Araragi has died due to Izuko Gaen. Mayoi Hachikuji was waiting for him in the afterlife, and guides him towards an unknown destination. Koyomi would have never thought that this certain someone would be waiting for him there.

Mayoi takes Koyomi to meet Teori, who offers him a way to return to the world of the living. Koyomi is in doubt about accepting his offer, as he believes others like Mayoi are more worthy of reviving than him, until he comes with a surprising decision.

After being exposed, Ougi is about to be engulfed by the darkness, but Koyomi refuses to give up on her and Meme reappears in the nick of time to save them.