Another Key

"Another Key" is the post-credit ending of Kingdom Hearts Melody of Memory. It uses in-game graphics and voice acting and ends with the phase "An Oath to Return".

Synopsis
At the Mysterious Tower, Kairi inform Yen Sid, Mickey, Donald, and Goofy about Riku's decision to go alone to Quadratum to look for Sora. Mickey, worried about Riku in a unknown world tries to go after him, but is stopped by Donald, Goofy, and Yen Sid. Yen Sid learning from Kairi that Terra-Xehanort has been researching about the other world since his time as an apprentice, but with the defeat of Xehanort, there is no one else who knows anything about the other world. Yen Sid, recalling from his days as a Keyblade Master that in the past, ancient Keyblade Masters had also crossed into the other world and that Terra-Xehanort was looking more deeply into it.

Yen Sid then tasks Donald and Goofy to gather the other Keyblade wielders in Radiant Garden, the Land of Departure, and Twilight Town to stop searching for Sora and inform them about what they have known about the other world. Kairi, wanting to go back to her Keyblade training wishes to learn under Aqua, which Yen Sid approves. Finally, Yen Sid task Mickey with learning about Quadratum and how it relates to the ancient Keyable Masters by sending him to Scala ad Caelum.

An Oath to Return

KINGDOM HEARTS

Characters in order of appearance

 * Riku, Terra-Xehanort, Xehanort, Sora, and Aqua are mentioned.