A young Rosalina finds Luma in a space ship that resembles the Starshroom. Rosalina waits with Luma for Luma's mother who was apparently coming for him on a comet. Rosalina gets tired of waiting so the pair fix up the spaceship and set off. Along their journey, they come across a comet. Luma gets exited and they land on the comet. Luma's mother was no where to be seen. They decide to stay on the comet and build themselves a home. One day another luma can to the comet, more and more kept coming. They all shouted "My mama! My mama!" as they circled around Rosalina. Rosalina became the adoptive mother of the lumas. Another day, she remembered her home planet. Luma, as thanks everything Rosalina had done for him, became one with the comet so Rosalina could see her homeland every 100 years.
- The Storybook was not planned to be in the game. One of the developers made it in their spare time.
- After all 120 power stars are collected, in the secret ending, there is a mossy spaceship in the Gateway Galaxy. It is assumed to be the same one Rosalina and Luma used.
- Like in the storybook, there is no glass in the windows.
- A book with similar appearance appears in Super Mario Galaxy 2. However, this book tells the story of Super Mario Galaxy 2 itself.