When a strange group of men attempt to kidnap Atsuko Fukune, a dancer at a club, she seeks the help of Mamiya Mugen, a famous detective - who also happens to be a child. When it turns out that other girls have gone missing, Mamiya, with the help of his butler Alucard, springs into action to solve the mystery.

Our heroine has been kidnapped and her two somewhat ditzy friends decided to save her in a war machine they found in her house. Unfortunately they have little idea of how it works so let the random destruction begin.