Prologue

“Every hundred years, a comet appears in the skies above the Mushroom Kingdom.
The comet was so large one year, it filled the skies and sent countless
shooting stars raining down. The Toads brought the shooting stars to the
castle, where they became a great Power Star. It should have been a very
happy time for the citizens of the Mushroom Kingdom. That was the night of the
Star Festival, held once every hundred years to celebrate the comet.

“Dear Mario,

I’ll be waiting for you at the castle on the night of the Star Festival.
There’s something I’d like to give you.

From Peach.”"

Super Mario Galaxy Complete Guide