Natsume Takashi has the ability to see spirits, which he has long kept secret. However, once he inherits a strange book that belonged to his deceased grandmother, Reiko, he discovers the reason why spirits surround him. Containing the names of these spirits, a binding contract was formed between the spirits and the owner of the book. Now, Natsume is determined to free the spirits and dissolve the contracts. With the help of a spirit cat, his days are filled trying to return the names to these spirits.