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, it uses in-game engine graphics, voice acting, ends with the phrase "Reconnect. Kingdom Hearts", and does not tease a future game, instead serving as the true ending of the game and a true prologue that leads directly to the events of Kingdom Hearts III.
Synopsis
As part of his mission, Luxu was the only apprentice who is not given a copy of the Book of Prophecies. Instead, the Master grants him possession of his Keyblade which possesses a Gazing Eye, which enables the Master to see into the future. Luxu is instructed by the Master to journey afar with the Keyblade and a strange box, which the Master tells Luxu never to open, and observe his fellow apprentices.
Luxu is traveling with the Master's Keyblade and the mysterious box and muses his Master's saying, "May my heart be my guiding key".
