Natsume's Book of Friends

While fooling around in the snow, Natsume and Nyanko-sensei run into Gen, a forest guardian who lives inside a statue. Gen tries to take over Natsume's body, but instead takes over a snow rabbit that Natsume had made. Gen pleads with Natsume to help him find an evil spirit who destroyed Sui, his guardian partner, and Natsume agrees. But it seems Gen isn't telling everything he knows. (Source: Wikipedia)