Senbei Norimaki visited Metropolis Island when he was a kid. He remebers that the city was particularly scary, but he can not remember why. Senbei (in fact a robot designed to look similar to him) visits Metropolis Island again, along with Arale Norimaki, Gatchan, Chivil, and Oinkety Oink. The group travel form Penguin Village to Metropolis Island on Taxi Dragon's back in order for Senbei to show one of his creations in a TV broadcast. While he is in the TV station, Arale, Gatchan, Chivil, and Oinkety Oink play war outside and destroy the city.