This book is a 20 format hardcover pop-up book. The book skillfully sets up multiple fold-out pages and mechanism pages, which significantly improves children's interest in reading so that children can continue to explore. The protagonist, the little boy Nao Nao, finds a magical cave. After entering the cave, he finds a plant kingdom. The surrounding plants are much bigger than him. He meets the same lost caterpillar in the plant kingdom and becomes good friends. At the end, Nao Nao helped the caterpillar find its parents. Many idioms related to plants in the story are explained and exemplified at the end of the book.