In the fortress humans now call home, a girl relegated to repair work wants to be a fighter, but her weary boss has long stopped fighting for anything.
Super spy Lance Sterling and scientist Walter Beckett are almost exact opposites. Lance is smooth, suave and debonair. Walter is… not. But what Walter lacks in social skills he makes up for in smarts and invention, creating the awesome gadgets Lance uses on his epic missions. But when events take an unexpected turn, Walter and Lance suddenly have to rely on each other in a whole new way.
U.C. 0079年10月。到地球战线赴任的年轻联邦军官西罗·亚玛达,在一次偶然的交火中,结识了敌人、也就是吉恩军的女驾驶员爱娜·萨哈林。这一对互相抱有好意的年轻人,因为分属敌对两方而不得不互相战斗,在战争中苦苦维持自己的感情;另一方面,西罗和他的第08MS小队的队员们,也在不断的战斗中逐步培养起友谊和信赖。
故事的舞台是在战争中被破坏的基地殖民地、飘荡着大量战舰的残骸的“Thunderbolt宙域”,宙域是对ZEON公国要塞“A Bao A Qu”的补给道路,为了夺回宙域,地球连邦军和ZEON公国展开了激烈的战斗。地球连邦军的伊奥·弗莱明少尉等人乘坐GM204F,潜入Thunderbolt宙域,向狙击手发起了挑战。