A corporate spy has infiltrated Nyamco, and Goro needs Mappy's help. Coincidentally, Goro has also gotten a new assistant around the same time as the reports of a spy...
The Nyamco office has become cluttered with trash, and the Prince of All Cosmos (the janitor) is out sick on Spring Cleaning Day. Without him to roll his Katamari around to pick up the trash, Mappy and Dig Dug will have to take his place.
Dr. Indie Borgnine has come to Nyamco to find a treasure that is reportedly beneath the Nyamco office. Goro has allowed him full access to the building, but Mappy disapproves.
The Ninja Assault Clan has cursed the Nyamco office building, and now 1,000 angry spirits are floating about, causing mayhem. Unfortunately, this is too much for Mappy to handle on his own.