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.

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.