In her sleep, Nanako is fitted with a special suit which enables her to be a war machine.
She can fly, shoot rockets, and fire bullets with the suit. She awakes to find herself in an exhibit showcasing the suit she is wearing.
During her display, in which only Satsuki can control, she is stopped by a robot named Griffith, which also destroys tanks and people in the process. Inside, a man named Alan Mizuki claims she is a cyborg named Nana-Go, which was shown to him by Dr. Ogami in their early days in college together. The once-friend of Dr. Ogami has now become his biggest rival, after sabotaging an attempt to revive one of his loves, Jamie. Nanako pleads that she is not a cyborg, but a human. Mizuki refuses to listen, and still believes she is a cyborg, because she cannot take the suit off.
Griffith is then released on her in combat, and eventually destroys half of the hospital. However, Mizuki drops the remote that controls Griffith, and that actives a mode which attacks anything that moves. While frozen, they try to figure out a way to retrieve the remote. When a rock falls from the ceiling, Griffith attacks it, giving them time to dash to the remote. Yet, their plans are foiled when a rock falls upon the remote and Griffith destroys it, destroying the remote also. It goes haywire and fires at everything in sight. Nanako is caught in the middle, and is forced to defeat the robot. She picks the robot up and throws it into the distance, defeating it, but also setting off a self-destruct sequence. It explodes, destroying Ogami Hospital.
Outside, in plain view of the wreckage, Nanako soon realizes her suit is running low on battery power. The suit soon falls apart, revealing her completely naked to Mizuki, proving to him she is not a cyborg. She realizes what happened and covers herself. Mizuki is then carried away by authorities, but Jamie rescues him on the way to jail by self-destructing herself. At the end, Dr. Ogami returns from seeing his father to see that the hospital is in ruins.