Rui Li works at a screw factory in Satellite City No. 9, a city on an unknown continent, where her job is straightening screws day after day. Over time, amid that monotonous routine, she comes to sense that something about the city is not real. Aided by a mysterious figure called Anull, she gains the power to transform and takes on the identity of Sirius, a thief who works in secret toward escaping the city. Once the truth about her world comes into view, Rui Li finds that her true fight is only starting. The twelve-episode ONA mixes action, comedy and fantasy.