Kingdom Hearts Unchained χ is the ninth title in the Kingdom Hearts series, and the first title available for iOS and Android. The direct sequel to the 2013 online web browser title Kingdom Hearts χ, it details the story of a Keyblade wielder leading up to the events of the Keyblade War.
The title was first announced on May 12, 2015[Verified source needed]. Kingdom Hearts Unchained χ released in Japan on September 3, 2015, with international releases the following year. The game was updated on March 23, 2017 and rebranded as Kingdom Hearts Union χ.