 The idea for an intermediary title was developed after director Tetsuya Nomura and his team had already begun to develop ideas for the second Kingdom Hearts game, which he had intended to be set a year after the original. Originally titled Kingdom Hearts: Lost Memories, Nomura changed the name to match the overall outline of the story, while still reflecting the theme of memories. Chain of Memories was developed to bridge the gap between Kingdom Hearts and Kingdom Hearts II. Like most sequels, Kingdom Hearts II was planned to have the character start from the beginning, ability-wise. To explain the loss of abilities gained in the previous game, Nomura had the story revolve around Sora's memories getting corrupted and implemented the card battle system to symbolize Sora's various memories.
