Year AD 2225. Kouji Aiba and Aoi Housen are serving as astronauts in-training in Liebe Delta which is located on the edge of the Geduld Sea. When saboteurs suddenly strike during a routine dive procedure, the space station plummets into the Geduld, a plasma field that links all the planets like a nervous system and crushes any ship that comes to to far into it. With all the adults onboard killed, the young astronauts have to survive the long journey home in the midst of growing tension amongst each other. Meanwhile the organizers of the sabotage prepare to attack once again.