Infinite Ryvius

The year is AD 2225. Kouji Aiba and Aoi Housen are astronaut trainees aboard Liebe Delta, a space station located on the edge of the Geduld Sea. When saboteurs with unknown motives suddenly strike during a routine dive procedure, the station plummets into the Geduld—a plasma field that links all planets like a nervous system and crushes any ship that strays too deep into it. With all the adults onboard killed, the young astronauts must survive a perilous journey home amidst growing inner tension. Meanwhile, the organizers behind the sabotage watch from the shadows, preparing to strike once more. Source MyAnimeList