Perky, spoiled blonde 12-year-old Ruridou Doris is an heiress to one of the largest advertising companies in Japan. So, naturally, she's sent to one of the most prestigious schools in Japan, one so large that it has its own subway system, and even a stadium for mecha combat. It just so happens that Doris, like one out of every ten people in her world, is a panzer, someone who transforms into a superhuman wielding a very large object that can be used as a weapon, like metal crab claws, vacuum cleaners, beam weapons, et cetera. Unfortunately one can not choose their appearance as a panzer, and not only does Doris have a tiny hand drill for a weapon, but she has another, larger one spinning on her head like a top! Needless to say, she does not look like heroine material, but as befitting the daughter of an advertising company, she must train beyond her abilities, and prove herself in panzer combat in the gigantic Central Stadium of her school, while risking such perils as school lunches, impromptu fan service photo shoots, and (worst of all) the utter lack of servants!