Tsugumomo

Kazuya Kagami wakes up in class from a bad dream to discover that he is inadvertently groping classmate Chisato Chikaishi's breasts. After escaping her wrath, Kazuya goes to the roof where he takes comfort in his mother's obi. Kazuya is attacked by a possessed wig and falls off the building, but is saved by his obi. From within the obi, a young girl, a tsukumogami, emerges. They are met by the host of the wig. The tsukumogami asks the host to sever their link with the wig, which the tsukumogami calls an amasogi or curse. However, the host and wig attack and the tsukumogami is forced to destroy the wig before disappearing. At home, Kazuya reflects on the day's events before falling asleep. After another nightmare, he wakes to find the tsukumogami in his bed. After avoiding a confrontation with Kazuya's possessive sister, the tsukumogami introduces herself as Kiriha and that she the tsukumogami of Kazuya's obi and that Kazuya is now her servant.

Kazuya and class rep Chisato find themselves trapped in the school library, and it's up to Kiriha's knowledge of spirits and the forms they take to get them out.

A towering priestess shows up looking for Kazuya, and the person who sent her has an offer he and Kiriha might not be able to refuse.

Kiriha is being battered by the water goddess Kukuri-hime's attacks, when a mysterious vision gives Kazuya advice on how he and the tsugumomo might manage to survive.

Now that Kazuya has accepted the duty of exorcising any supernatural trouble that crops up, it's up to Kiriha to whip him into shape.

When the entire school starts acting like characters from a dating sim, Kazuya and Kiriha are forced to find the amasogi responsible before the affected people do something they'll regret.