I just started this series a few days ago and god damnit its a really cute series. <333
The translated title is "Natsume's Book of Friends" (lawl you'll see why).
The serie is about this boy named Natsume who discovers a book called "The Book of Friends" left by his grandmother Reiko. "The Book of Friends" was a book that contained all the names of yokai that Reiko defeated and made her servants (badass grammy haha xD). When she beat them in battle they would sign their names on paper, and she would become their master.
Anyways since Nasume is also a lot kinder then his grandmother, he becomes friends with the Yokai who Reiko captured, and works to give their names back to them and set them free.
Along the way he meets Murata. I large and elegant dog or wolf yokai who has taken on the form of a "Lucky Cat" and is nicknamed 'Nyanko-sensei'. Nyanko-sensei says that once Natsume dies he gets ownership of the "Book of Friends" (cuz whoever posses it gains control of all the yokai listed in it). Till then he becomes Natsume's bodyguard and friend.
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Overall this show is kinda episodic like the anime Hell Girl, but it has a feel lke the anime Tactics. If you enjoy either on of those you'll really like this show. <333