High school senior Koyomi Araragi discovers a shocking secret one day after helping his classmate Hitagi Senjougahara—a secret he is never to tell.

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.

Meme is not himself these days, caused by Shinobu’s disappearance from the house. Koyomi, Mayoi, Suruga and Nadeko all search for Shinobu.