An amazing anime about a boy and how he can see supernatural spirits.
[Edit]Natsume Takashi is a high school student who has the ability to see youkai (monsters) ever since he was born. One day, he accidentally breaks a seal which contained a very powerful youkai, a cat which had heard and was after a particular source of power, called 'The Book of Friends' (Yuujinchou). The person who had claimed the book was called Natsume Reiko and the cat set out to find her. After having Natsume Takashi tell him that he had the Book of Friends and that Reiko had passed away, the cat (which is then named Nyanko-sensei and his real name Madara) then makes a deal with him that he'll be his bodyguard and claim the Book of Friends when he passes away. Natsume agrees to this and a series of adventures begin.