The seven rainbow bridges, connecting the seven rainbow islands, have disappeared. King Dedede is to blame as always... or is he? The evil Dark Matter has him under his control and plans to turn Dream Land into a dark world. Kirby aims to save the day by going through seven worlds, aided this time by three animal friends (though you never see Rick the Hamster used in this run).
To get the true ending to the game, the player has to find a rainbow drop on each island, which form the rainbow sword after the main showdown with Dedede. These rainbow drops are hidden off the main paths of the stages, and most of them require a special power to break the barrier guarding the drop. This has a large effect on the route in some stages.