Far long time ago, people in a planet named ESC, which had ruined in a military coup d'état, have immigrated and developed a highly scientific and technological city on Mars. Minami, Sam and Sheena started on a trip for the sake of the duty to search for their mother planet.

After one month, they received a message, "EMERGENCY happened!", and after that they could never have a contact with Mars. So they returned from the trip as soon as they could. But only they could find is that the city has disappeared from Mars without any evidence.......