Kannami Yuichi is a "Kildren", a fighter pilot recently sent to Urisu Base to replace a previous one who had died in battle. Like the numerous genetically-engineered pilots before him, he does not age, only to live his life fighting and eventually dying in battle. Rostock and Lautern, 2 different companies have been engaged in a brutal war that has no beginning or end, rather the battles they create serve to "entertain" the peacetime people. Yuichi befriends the base commander, Kusanagi Suito, a woman who endures a long dark past. As their relationship grows, Yuichi learns the bittersweet moments of life, and the inescapable fate he has been placed in. The film adapts Hiroshi Mori's military romance novels that are set in an alternate-history world.