Azuma Kiyohiko manga
Ever since the conclusion of Avatar: The Last Airbender, its millions of fans have been hungry for more - and it''s finally here! Think of this as the Book Four (season 4) of Avatar because it continues Aang's story from right where the TV series left off. This series rejoins Aang and friends for exciting new adventures, beginning with a face-off against the Fire Nation that threatens to throw the world into another war, testing all of Aang's powers and ingenuity.
Avatar Aang asks his friends to help him honor Yangchen's Festival - an extremely sacred Air Nomad holiday that has not been held in over a hundred years. However, cryptic visits from the spirit of Avatar Yangchen herself lead Aang to discover a jointly owned Fire Nation and Earth Kingdom refinery - operating on land sacred to the Airbenders! Is this the cause of the pollution Aang finds there, or is something more mysterious happening?