I just finished all the episodes that have been released so far of what has become one of my favorite animes of all time, Natsume's Book of Friends.
It's about a teenage boy who's been able to see spirits all his life called youkai, which is a Japanese kind of unseen monster, like a nature demon. They don't interact with humans all that much, who can't see them, but Natsume can. Some are friendly, some are terrible, nearly all are extremely selfish (very like the demons on SPN).
When he was younger, he didn't understand what they were or what was going on (in this way, it's got some things in common with the movie The Sixth Sense). He was always strongly reacting to things that terrified him, but since no one else could see them, he was accused of lying and trying to be strange and scare people. Orphaned at a young age, he was passed around from relative to relative, none of whom wanted him or could handle him, some of whom treated him badly.
However, when the show starts, he's living with some distant relatives who did want him and are kind, in a peaceful rural town. He's still flinchy and formal with these folks, after having been cast out so many times. He still has encounters with youkai, some of which are damaging and dangerous, and he might come home covered with leaves or dirt or scrapes, or be out all night or what-have-you, but they're patient and understanding, although they don't know about his special ability to see things.
He's also managed to make some friends at his high school. He's gotten much better at hiding it when he gets freaked out, but sometimes he still inevitably acts weird, and his friends are also nice and tolerant and understanding. Some of them even learn his secret.
The show has a marvellously consistent aesthetic and atmosphere: gentle, melancholy, beautiful, poignant. Rare is the episode that doesn't bring a tear or two to your eye by the end. The theme is generally about finding love and acceptance after being without it all one's life, how precious he finds his family and friends--both human and youkai, for he puts a lot of effort into helping youkai, who then in some cases feel compelled to return the favor, and love him in their strange way.
The "Book of Friends" is a book left him by his grandmother who could also see youkai, who challenged them to a fight or a game and, if they lost, took their name and wrote it in the book, which made them have to serve her, if called, so youkai are constantly coming to Natsume to demand their names back, and he does his best to give as many as he can.
He also has a youkai helper and protector who usually takes the form of a doll-like cat, whom they kind of jokingly call Nyanko-sensei (which translates basically as "Master Kitty-Cat"). He claims he's only there to protect him until he eats him (youkai like to threaten to eat humans, as well as smaller youkai) and takes the book for himself, making all the youkai in it his servants, but Nyanko-sensei also loves him after his fashion, despite his hard-partying ways. (... Yeah.)
We just finished watching the fifth season, and it's already been greenlighted for a sixth. It's kind of a slow-burning show to have become so popular, but it is kind of popular now--yay! I really can't recommend it enough if any of this sounds like your cup of tea.
I admit to being disappointed in the fifth season, though. The OVA was so boring it was hard to get through. Meanwhile, though throughout the series most of the episodes focus on Natsume and his friends and his adventures with youkai, every season there's been an episode or two that's money, a feels bonanza, doing a flashback to Natsume's difficult youth, or someone new learning his secret, or an outside POV, or learning more about his relationship with his new parent figures.
I expected the episode named after these parent figures to be such an episode (the penultimate episode of the fifth season), as it was to be all about how they decided to take him in. Instead, they filled the time allotted for the episode with the mother figure fretting about shopping and cooking, never revealing anything particular that wasn't already known, and not developing the parent characters at all; it was a big disappointment.
Then the final episode of the season was about the "mid-level youkai," as if we were all just dying to learn more about them, and how they found some flowers they thought Natsume would like. (!) As much as I love this show, I had to turn to my friends and say, "I think they've run out of ideas," and they had to reluctantly agree, so keep that in mind as you embark on the series, if you decide to.
To me, the series always seemed to be headed in the direction of fulfilling all this potential: for everyone to finally learn his secret, including his parent figures; for his past to be fully revealed; for him to grow and change, to become more confident and to feel more at home in his home and with everyone he knows; basically, for him to grow and change, and for his relationships to grow and change. I was greatly looking forward to it! Alas, it's beginning to look like this was not their intention with the series.
Still, what's already been made of the show is fantastic (except for, as mentioned, a rather weak fifth season), and I highly recommend it.