The near future. A horrific battle against a parasitic virus known as "Gastrea" has been fought...and lost. Humanity is cornered and lives in despair. Rentarou and Enju face constant danger in their work as a team of specialists for the Tendo Civil Security Agency, one of several groups dedicated to fighting Gastrea. Enju is one of the "cursed children," who survived the virus and gained superhuman powers as a result. A crazed top-hat-wearing terrorist is on the loose, but Rentarou's got his hands full just dealing with his fellow civsec agents!