Invited to a wealthy client's mansion, time-traveling witch Yuko and her companions arrive to find a group of collectors assembled to participate in a mysterious auction. And the mystery only deepens when the collectors go missing one by one. As more guests disappear and strange occurrences abound, Yuko and her friends realize they must solve the mystery before they vanish as well.

Kimihiro Watanuki can see spirits and other assorted supernatural creatures, which is quite a bothersome ability he strongly dislikes. On the way home one day, while plagued by some spirits, he is inexplicably compelled to enter a strange house. There, he encounters Yuuko, a mysterious woman who claims to be able to rid him of the ability to see and attract the troublesome creatures—for a price. She demands that he work at her "store" that grants wishes to people, and thus begins Watanuki's adventures through weird and wonderful events.