In May 1945, as Soviet troops close in on Berlin, a group of sorcerers completes a ritual fueled by the war's mass casualties and vanishes without a trace. Decades later in present-day Japan, high schooler Ren Fujii is still recovering from a fight with his best friend when that same group, the Longinus Dreizehn Orden, resurfaces with apocalyptic plans. Forced to wield abilities like the ones his enemies have, Ren has to protect the people around him from a threat rooted in the war's final days.