Paper Mario is the second RPG starring Nintendo's mustachioed mascot, and the first in the successful Paper Mario series.
After Intelligent Systems was chosen to make a sequel to Super Mario RPG, the team had issues figuring out how to make the game thematically different from the main series Mario games. The team tried to use polygons, but the idea was rejected. The team broke into three groups that worked in parallel to create sample models.
Naohiko Aoyama, a new employee at the time, ended up creating a rough image during his downtime that involved 3D models but looked like a picture book transplanted into a video game with paper-thin 2D backgrounds and characters. Aoyama conceived of this art style by going against the trend of realistic 3D graphics; instead, he thought it would be interesting to use the 3D capabilities of the N64 to further emphasize a 2D game.