While two children, Poke and Piki, are reading a story, a monstrous hand suddenly appears from inside the pages and kidnaps them. When the rest of the Dream Factory family hear their cries of help, they jump into the story and help save them from the evil Wart.

The game was released as part of the Yume Koujou '87 event (sometimes referred as Dream Machine, in English), which was sponsored by Fuji TV, and stars its mascots.

The game was edited and released as Super Mario Bros 2. Due to Nintendo of Japan feeling like their version of Super Mario Bros 2 would be too difficult and outdated by the time it got to the United States.

The game takes place inside a storybook. The book's story tells of the dream world of Muu, where the quality of dreams determined the quality of the weather the next day. Because of this, the Muu citizens invented a dream machine so they could always have good dreams. One day, a mischievous being named Mamu invaded the land and used the dream machine to make nightmarish monsters. However, the Muu people learned of his weakness to vegetables and used them to defeat him.

The old storybook had found its way into the hands of a pet monkey, Rūsa, who gives the book to the young twins Poki and Piki. However, the twins quarrel and end up ripping out the last page of the book, causing its ending to be erased. Mamu, freed, reaches through the pages and grabs the twins, pulling them into the book. Rūsa gets the twins' parents, Mama and Papa, their brother, Imajin, and Imajin's girlfriend, Lina, and they enter the book to rescue them.