A/N: FFXIII and Super Smash Bros. Brawl are both owned by Square Enix and Nintendo. Story I dea however is mine.

Prologue: the disappearance of Pichu

Long ago, in a bizarre world crawling with many warriors, anthropomorphic and demons from various kingdoms and cities that never were to exist in this borderline world they would call home. This home they live in was known as Smash world.

One week had passed since the tournament, Tabuu's mischief, and an oddly disappearance of a fellow smasher. Her disappearance made the rulers of Smash World, Master Hand and Crazy Hand, keep check of the contenders, hoping that no more would vanish again. But that didn't that no one of the Smash Mansion had to be cooped up in the mansion.

Two out of the many smashers wanted to chill out in the Forest sector of Smash World and have a picnic with DiddyKong and Jigglypuff. Pikachu and Kirby wanted to do that to take their mind off the lost Smasher, especially Pikachu. He really cared about her a lot even though they were different in age but sometimes thought of her as a little sister he never had, or even something else. Hell, with his human partner, Ash, he had a family, but with her he felt as though when she was old and mature enough, then he would have asked her how she truly felt about him.

"Poyo, Pikachu? (What's wrong, Pikachu?)" Kirby asked his yellow companion.

"Pi? Pika Pikachu Pi (Eh? Ah, nothing, Kirby)" Pikachu replied to his pink, 'marshmallow' friend.

Kirby was always worried about his friend Pikachu after 'she' vanished one week ago from today. Since then he promised to himself that he will help Pikachu cope with her gone and find a way to bring her back home. He stopped in his tracks in front of Pikachu, startling the electric mouse by lightly punching his friend's he and tried standing tall to make his friend smile with his confident voice:

" Pikachu, poyo, Kirby, poyo poyo poyo poyo~~~~~~~!( Pikachu, I, Kirby, solemnly promise that I will help you find Pichu and bring her home safe and sound~~~!)"

This made him laugh and Iron-tailed Kirby on the head, thanking him for cheering up. They made a rest stop by the Plain sector which leads them to their destination, thinking of a strategy and prank for their two friends who were waiting for them. Just because the tournament is over doesn't mean the Smashers also can't brawl outside the mansion walls. They silenced their battle-strategy chat when they heard an ominous song playing through the wind and sky. Many Smashers thought whenever there's singing, it's the Oracle, Naryu, singing. However this voice was very different in some way… It was a mind- possessive song. Pikachu knew something about this song was cruel and wasn't effected by its dark melody. Kirby, on the other hand was not so lucky.

And this was only the beginning of their troubles.