Yes, Natsume's Book of Friends is definitely worth watching! The show tells the story of Takashi Natsume, a boy who can see spirits, and the relationships he forms with the spirits, who look like animals and sometimes have a human form. Takashi uses the book of friendships that was given to him by his Aunt Reiko, to be able to communicate with the spirits and help them figure out their unresolved problems.
The show is incredibly well written and develops each of its characters in an incredibly detailed and meaningful way, making it a truly heartwarming experience for the audience. The stories it tells about the friendship between Takashi and the spirits, and the struggles he faces in dealing with his gift are both thought provoking and emotionally engaging. And with several arcs about specific spirits and their issues, the show slowly builds up its world and its characters in an almost cinematic style, as it slowly reveals more about the protagonist's past with each episode.
Overall, Natsume's Book of Friends is a show that's truly full of heart and perfect for fans of fantasy and slice of life anime. It has a great plot and some amazing character development, making it a truly delightful experience.
