Hanaukyou Tarou, a high school student whose parents have died, is forced to move to Tokyo into his grandfather's residence. However he does not know that his grandfather is very rich and that he left the residence (with all the staff) to Tarou.

The staff is composed only of professional maids and there are many of them in the house! Unfortunately Tarou is allergic to women and changes colour whenever they touch him (and because they were used to their previous master's habits they touch Tarou a lot!). But there is one maid named Mariel whose touch has an opposite effect on Tarou.

Loran Cehack, a member of the lunar Moonrace, is sent to Earth as a scout for the return of his people to their mother planet. But Earth's rulers have formed a militia to oppose the handover of their land to these aliens. With their outdated biplanes and fighting vehicles, the people of Earth are utterly helpless in the face of the Moonrace invasion and its huge walking robots. Then Loran discovers a relic from the space age, a mobile suit called Turn A, and becomes the last hope of Earth's militia.