Crunchyroll has confirmed that the sixth season of Natsume Yūjin-chō (Natsume's Book of Friends) is the latest heavyweight to join the already crowded Spring anime season. The fifth season wrapped this December and confirmed that a sixth season was in the works but fans of the Yuki Midorikawa adaptation certainly didn't expect it to debut so soon. As with previous seasons, Crunchyroll is the likely platform that will simulcast the show and with their new deal, Funimation may even provide a dub.
About Natsume's Book of Friends
Yuki Midorikawa began the shojo manga in 2005 in the shōjo manga magazine LaLa DX. The story follows an orphaned teenager named Natsume who inherits his grandmother's magic notebook, which can be used to bind spirits, which she called her Book of Friends. However, where his grandmother forced spirits into servitude, once the notebook comes into his possession, the kindhearted Natsume begins the lengthy process of unbinding these contracts and setting the spirits free. Word of his deeds quickly spread, attracting all manner of spirits seeking his help and also those with malicious intent, desiring the notebook for themselves.
Brain's Base animated the first four seasons before giving way to Studio Shuka in season 5. Shuka will also produce season 6.