Takashi Natsume is a 15-year-old boy who wants nothing more but to live a normal life like everyone else. But to his dismay, like his deceased grandmother, Reiko, he possesses the ability to see "youkai," or spirits. Natsume eventually discovers that Reiko had bequeathed to him a book of contracts in which she had bound youkai—the "Book of Friends." However, without Reiko ever calling upon the spirits' names, they have been left in a confined state. Now, these spirits continuously pursue Natsume