"Natsume's Book of Friends" is a Japanese manga and anime series created by Yuki Midorikawa. The story follows Takashi Natsume, a high school student who can see youkai and spirits. After inheriting a book from his grandmother, he discovers it contains the names of various youkai she had bound to her service. As Natsume seeks to return the names to their rightful owners, he forms a bond with Madara, a powerful spirit in the form of a lucky cat. The series explores themes of friendship, loneliness, and the connection between humans and the spirit world.