In Penguin Village, humans live alongside talking animals and objects. Senbei Norimaki is one of these humans, and he's an inventor with the lofty dream of creating the world's best robot girl. The product of his efforts is Arale, but depending on your definition of perfect, she's anything but! Not only is Arale severely nearsighted, but she also has no common sense! At least she has super-strength, though that often proves to be a setback as well. Although she means well, Arale only causes trouble for her neighbors in the whimsical Penguin Village!

The story revolves around Sally's search for her grandfather Dr Borman, a researcher who worked on the Zi-Forming scheme. He bestowed her a pendant at the start of the series, with instructions to never hand it over to the Empire. A competing researcher for the Empire: Dr Land seeks to find Sally's pendant. The pendant is shown to possess strange powers, transforming Leo's Zoid into the Beast Liger, and later interacting with Regeneration Cubes - artefacts left over from the failed Zi-Forming scheme. As Leo, Sally, and their comrades journey, they begin to uncover more of what the pendant can do, the relationship between the two scientists, and how it all relates to the Zi-Forming of Earth.

Momo and Komomo can deliver mail from anyone, to anyone. To anywhere in the world, the galaxy, or the universe. Under the sea, high up in the clouds, and around the corner. To the past, the present, or the future. They both work tirelessly to insure that the important letters of people are delivered, while Komomo also works hard to keep the ever distracted Momo on task. (Source: ANN)

Dr. Slump creates a little android girl, Arale, who is very stong, happy, and totally common senseless. They live in Penguin Village where the strangest things happen (e.g., the dawn is announced by a little pig wearing a basquee).