The "Nyanbo" are beings from outer space with square bodies, ears, and tails that arrived on Earth. Tora, who want to fix their wrecked UFO and return to space, is joined by his sister Kotora, the precocious Shiro, the mischievous Mike, the mysterious Kuro, and a slew of other characters. All of these Nyanbos are now living contentedly in locations that people are unaware of, much like cats, free-spirited and occasionally getting into mischief.