In an unknown continent, there is a city called Satellite City No. 9. Rui Li, a screw straightener in the screw factory in the city, gradually realized the unreality of this city during her boring work day after day. With the help of the mysterious character "Anull", Rui Li gained the superpower of "changing clothes" and transformed into the thief "Sirius" to secretly escape from here. When the truth of the world finally appeared before her eyes, Rui Li realized that her real battle had just begun...