Uncomfortable after quarreling with his sister on Mother’s Day, Koyomi leaves the house. Hitagi bumps into him at the park and makes an offer.

Koyomi and Hitagi meet a girl named Mayoi Hachikuji in the park. She seems to be lost and cannot find her way home. The two try to help her.

An apparition is behind why Mayoi is unable to reach her mother’s house. Receiving advice from Meme, Hitagi tells Koyomi the surprising truth.

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.