Chuuta Kokonose is an orphan who lives with his aunt. For as long as he can remember he's had a voice in his head, but other than that he's been a normal boy—right until the day when a strange thing follows him home and teleports him to a place filled with even more fantastic creatures. It's a police station in space.

Surprisingly, Rein Brickke, the Chief of the Solar System Department, tells him that their computer chose him as a potential candidate for the solar-system's police force. However, Misuzu Sonokata, a girl from Chuuta's school with an angelic face and ill temper who turns out to be one of Rein Brickke's subordinates, doesn't think Chuuta is suitable for such a job.

Although Chuuta was shocked at first, he decides to take the aptitude test after being urged by the voice in his head. Most importantly, he wants to prove Misuzu wrong.