Forbidden Pop-Up Book

The Forbidden Pop-Up Book is a major plot device of Yoshi's Universal Gravitation. It is a book filled with spirits, and owned by the greatest spirit of all, Hongo.

In the beginning of the game, Hongo uses his magic to try to stop Bowser, who is trying to conquer Yoshi's Island with his armies. However, Hongo fails and he and Yoshi's Island are inserted into the book. In the Forbidden Pop-Up Book, Yoshi, helped by some spirits, goes on a quest to defeat Bowser and save Yoshi's Island.