Mugen no Ryvius

In the year AD 2225, astronauts-in-training Kouji Aiba and Aoi Housen are serving on the space station Liebe Delta, located on the edge of the Geduld Sea. When saboteurs launch a surprise attack, the space station is sent plummeting into the Geduld, a plasma field that connects all the planets and proves fatal to any ship that ventures too far into it. The incident results in the deaths of all the adults on board, leaving the young astronauts to fend for themselves as they navigate the treacherous journey home amidst growing tensions and rivalries amongst themselves.