Chūta 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 a normal boy - right until the day when a strangely-looking thing follows him home and teleports him to a place filled with more fantastic creatures. It's a space police station, and Rein Brickke, the Chief of Solar System Department, tells him that he's been chosen by the computer as a possible candidate to join the police force, although Misuzu Sonokata, a girl from Chūta's school with an angelic face and ill temper who turns out to be one of Rein Brickke's subordinates, doesn't think him suitable for such a job. Chūta, who was shocked at first, decides to take aptitude test after being urged by the voice in his head and to prove Misuzu wrong.