Heart & Key

Heart & Key is the ending of Kingdom Hearts χ Back Cover. Like Blank Points, Signs of What's Next, and Another Guardian of Light, this cutscene utilizes in-game graphics and voice acting. It ends with the phrase "Reconnect. Kingdom Hearts," and it does not tease a future addition to the Kingdom Hearts series. Instead, it serves as a true ending and acts as a prologue to Kingdom Hearts III.

Synopsis
Luxu stands alone in a barren wasteland. With him are the mysterious box and Keyblade he inherited from the Master of Masters. Luxu studies his new weapon for a moment, and he looks to the sky as he says, "May my heart be my guiding key."