To obtain this bonus, you'll need (1) Sawaru Made in Wario DS game and (2) Mawaru Made in Wario GBA game.

Insert Mawaru into the GBA cartridge slot of the DS and Sawaru into the DS game slot.

Turn on the DS and start Sawaru. After pressing the Start button in the game, a new bonus item will appear and you can click on it to watch Mona Pizza's promotional video.

The video uses 2 screens with cut-scene animations of similiar quality to the other cutscnes in the game and the voice of the TV girl singer in the Mawaru game will can be heard singing Mona Pizza's theme song and lyrics to the song is displayed.