the manga is based off a popular ps2 game of the same name that involves characters from both disney and final fantasy games, using original characters for the MC. the manga itself is more loosely based though as only taking key parts of the game and turning it into manga, so you're not really getting the full story, just the really important stuff. its basically "kingdom hearts in a nutshell" in a manga. its only really enjoyable if you already played the game. its easy to find copies online so if you're a KH fan then go ahead and buy, but if you're not familiarwith the series itself its best to stay put