The action takes place in a post-apocalyptic world, where the main government is ruled by by the calculating church. The world is swarmed with the living dead, which are corpses that have been affected by an unknown curse. In order to combat this, the church employs people,necromancers who wield powers to defeat these evil creatures. Tsukasa Yugi and Amane Yugi were taken from their family by the church when their seals appeared at age 4 and nurturing to kill the Living Dead going on missions as ordered. The Yugi twins are young necromancers tasked by the church with defeating the living dead that swarmed towns and wreck havoc. Their permanent seals can summon a firearms used to kill the living dead.