Mametchi and his friends spend their time traveling into storybooks at the library. They come across a book called "The World's Happiest Story", which is about a character named Happy who is trying to get, well, happy, and eventually it's revealed that a page is missing from the book. Their friend Kikitchi jumps into the book, which is enough to affect Tamagotchi Planet as well as the world in the story, forcing Mametchi and friends to save the day.
Cartoon Network aired an English dub in the Philippines.
Succeeded by Tamagotchi.
This film contains the following tropes:
- Banana Peel: Kikitchi throws banana peels onto the ground to make Memetchi and Makiko slip due to him being jealous about their interest in the magical books.
- Big "SHUT UP!": Kikitchi says this to Hapihapitchi after she fails to make him happy.
- Call-Back: The Mametchi Fan Club from Let's Go! Tamagotchi appears as the story begins. Young Mametchi calls out Makiko for violating rule #8, which forbids members from going to Mametchi on their own.
- During the credits, a picture of Tanpopo from Tamagotchi: The Movie can be seen.
- Disney Death: Near the end of the film, Hapihapitchi runs out of happiness to absorb and dies. Then Happy says he's the happiest man alive, which revives her.
- Giant Food: One of the storybook worlds is filled with this.
- The Movie: The second movie to be based on Tamagotchi.
- Non-Indicative Name: Happy is not actually happy, but he's trying. This changes by the end of the film, of course.
- Portal Book: The Tamagotchis are shown traveling into books in this film. In fact, it's a central plot point - they have to help Kikitchi get back to the real world from "The World's Happiest Story".
- Save Both Worlds: Mametchi and friends must save both Tamagotchi Planet and the world in "The World's Happiest Story".
- Show Within a Show: A book within a film, more like. "The World's Happiest Story" was invented specifically for this film.
- Trapped in Another World: Kikitchi gets himself trapped in "The World's Happiest Story", and Mametchi and friends must rescue him.