Kai Nagisa, a normal high school girl who wishes to one day become a professional wrestler (despite having a strong cowardly side), is suddenly approached by a robot known as an Iczel. It urges her to help save the Earth from invading aliens under the command of the brother and sister team Chaos and Cross. To do this, Nagisa must merge with Iczel and become one of the battle-suited warriors that protect planets throughout the universe-- an Iczelion. She is understandably reluctant to take up this sudden unbelievable task and fight with the other Iczelions of Earth. There may be little choice, however, as the invading forces have already arrived and won't stop until they have achieved the destruction of the planet.