Natsume is an ordinary boy in everything but one: he inherited from his grandmother Reiko the ability to see spirits. Reiko intimidated the spirits and fought with them - the losers wrote down their name in a friendship notebook, thus concluding a contract with Reiko, under which they should help and obey her. Natsume inherited this notebook, and now he will have a hard time because of the hordes who want to take it from him ...