Aoi Wakatsuki is a live-in maid in the home of Toshiaki Kaidou, chief of the National Police Agency. On the surface, this 17-year-old girl is just a maid looking after house and master. But in truth, she is an evil-hating, justice-dispensing, maid detective! Her mission: to infiltrate stately mansions that the police can't investigate and bring to light any crimes hiding within. "Evildoers, the maid from hell is waitin' for ya!"