In the year 2021, a parasitic virus known as "Gastrea" infects humans and turns them into monsters. What is left of mankind now lives within the Monolith walls, walls that are made of Varanium, the only material that can hurt Gastrea. To counter the threat that the Gastrea pose, "Cursed Children"—female children whose bodies contain trace amounts of the virus which grant them superhuman abilities—officially called Initiators by the Tendo Civil Security, are given partners called Promoters, people who work to guide and protect the young Initiators. These teams of two are sent out on missions to fight the monsters created by the Gastrea virus and keep them at bay. Black Bullet revolves around the team of Enju Aihara, an Initiator, and Satomi Rentaro, a Promoter, as they go on missions to fight the growing threat of Gastrea in their hometown of Tokyo. A near future, where humans have been defeated by the viral parasites named Gastrea. They have been exiled into a small territory and live in despair, side-by-side in terror. In this world trapped in darkness— Rentaro, a boy living near Tokyo and member of the "Civil Security"—an organization specializing in fighting against the Gastrea—is used to accomplishing dangerous tasks. His partner is Enju, a precocious young girl. They fight thanks to their peculiar powers until one day, when they receive a special assignment from the government. This top secret mission is to prevent the destruction of Tokyo... Set in a near future, this thrilling heroic-action story... starts now!