The only story unlocked at the beginning of the game. It involves King Dedede of course. Although it;s hard to say wether he's an antagonist or a protagonist. I suppose he starts out as one, then becomes the other, respectively.
King Dedede is making ridiculous rules as the king of Dreamland! But he goes too far when he requests all of the inhabitants possessions, and anyone who refuses is thrown in Dedede Dungeons! Once again it's up to kirby to save the day.