Poki and Piki are reading through an ancient storybook that tells about a dream machine that lets everyone have good dreams. However an evil being called Mamu invaded the land and used the machine to create nightmare instead. When their argues rips one of the pages asunder, Mamu is unleashed who quickly kidnaps the twins onto the world of dreams. It's up to their family to rescue them; where the player can choose between four different characters, Mama, Papa, Imajin their brother and Lina, Imajin's girlfriend - inspired by Arabian themes and all unique abilities.

The game was initially made as a promo by Fuji TV in collaboration with Nintendo to promote the Yume Kōjō '87 event which showcased upcoming TV shows. Seeing as the game eclipsed Nintendo's original Super Mario Brothers 2 (known as Super Mario Bros.: The Lost Levels in the West), they used the opportunity to replace the protagonists, creatures and story with Mario characters and released it in Europe and the West as Super Mario Bros. 2.

While both games are similar, there are many differences to adhere more to the Mario universe. Like 1-up mushrooms instead of icon of the character played, all playable characters have been switched out for Mario, Luigi, Princess Peach and Toad and it's possible to switch what character to play between each level.