Yūko Inoue is a high school student forcibly captured by the Telephone Pole Gang. They subjected her to experimental cybernetic modifications, transforming her into a cyborg implanted with missile weaponry. This traumatic process resulted in a personality marked by heightened emotional volatility, persistent angst, and stubbornness.

As a central figure in the conflict, her involuntary cybernetic modifications trigger uncontrolled activation of the missiles integrated into her body. This unleashes widespread destruction and chaos. The Prefectural Earth Defense Force intervenes to rescue her from the Gang's control. Despite her retrieval, the unstable cybernetic weaponry embedded within her remains an active source of unintended calamity.