Koyomi Araragi begins the day by being rudely awoken by his sister, Tsukihi. He decides to discuss love with her, asking how one can tell if they are in love or not. It turns out that recently, he can't stop thinking about his classmate, Hanekawa Tsubasa. Later, he runs into Hanekawa, who reveals a shocking fact which he may not tell anyone else about.

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.

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.

Koyomi Araragi and Shinobu Oshino discuss the true nature of Shikigami doll Yotsugi Ononoki, and Koyomi is being rudely woken up by his sisters who tell him to cram for his upcoming college entrance exams.

Koyomi Araragi sees that he has no reflection, and discusses this with Shinobu. She then suggests that Koyomi should see Yozuru Kagenui and Yotsugi Ononoki.

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.

Nadeko comes over to Koyomi's house, and is pleasantly surprised that Koyomi's parents and siblings are all absent. The two then engage in a discussion about Kaiki's curse and his means of spreading the rumor amongst the middle schoolers in town.

Tsukihi consults Koyomi regarding her Tea Club members on why her fellow members still believe in the ghostly "eight member" despite Tsukihi proving the rumor was fake.

On his way home, Araragi sees Yotsugi, who asks him for help finding something.

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.

Now fully human again, Koyomi is called by Hitagi for a date, as they spend some time together, Koyomi has a vision of Ougi.

To stop Ougi from meddling further, Koyomi has a final confrontation with her.

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.

Koyomi Araragi contemplates the current state of his life post-graduation when he suddenly gets pulled through the mirror into a mysterious yet familiar world...