The primary antagonists in "Tokyo Mew Mew" are aliens who appear on Earth to "reclaim it". According to the aliens, their ancestors lived on Earth three million years ago, but left after a series of catastrophes nearly led to their extinction. The aliens ended up on a planet with an inhospitable surface environment and were forced to live underground by sandstorms and high temperatures. They never forgot about Earth, and when they return they are disgusted by the human inhabitants, as they feel that humans are destroying the planet. The aliens use Chimera Animas to accelerate the humans' environmental damage to destroy all life, and reclaim the planet.