KINGDOM HEARTS χ Back Cover was an extra cinematic added to the KINGDOM HEARTS HD II.8 Final Chapter Prologue collection, meant to cover important behind-the-scenes events that took place during the events of KINGDOM HEARTS Union χ. The idea was that players could watch this movie (clocking in at a little over an hour) and understand all of the relevant information from KINGDOM HEARTS Union χ in order to go into KINGDOM HEARTS III with the proper context.

However, KINGDOM HEARTS χ Back Cover raised many more questions than answers, and still didn't really explain any of the events of KINGDOM HEARTS Union χ. Instead, fans were given an hour-long movie that did provide important insight, but not so much into KINGDOM HEARTS III as it did into what could possibly lie beyond KINGDOM HEARTS III.

KINGDOM HEARTS χ Back Cover was also included in the KINGDOM HEARTS ~The Story So Far~ collection for PlayStation 4.

This collection was a 2-disc set that came with KINGDOM HEARTS HD I.5 + II.5 ReMIX as well as KINGDOM HEARTS HD II.8 Final Chapter Prologue. There was nothing different about this iteration of KINGDOM HEARTS χ Back Cover compared to its inclusion in the KINGDOM HEARTS HD II.8 Final Chapter Prologue collection; it was simply a repackaged collection to include every KINGDOM HEARTS remastered title in one bundle.