two years have passed since the third battle of mars, with the nadesico taking possession of the ruin. the earth and the jovian federation have come to an uneasy peace. however, akito and yurika have both vanished and are presumed dead. meanwhile, a new threat to peace is rising in the form of the "martian successors" (a splinter group of the original jovian federation who wish to continue the war and take revenge on the earth and nergal and bring about a new world order). a 15-year-old ruri hoshino, is now the new captain of the highly-mobile battleship "nadesico b", and has earned the respect and awe of many in the military thanks to her unparalleled skill with machines, made her gains the nickname "cyber fairy".