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!

When Haruhiro awakens, he’s in the dark surrounded by people who have no memory of where they came from or how they got there. As the darkness fades, a fantastic new world called “Grimgar” appears before them and their adventure begins—but first, they’ll have to choose their guild, class, and special abilities.

Sakaido is a genius detective who can track down any criminal. But when his daughter is murdered, revenge lands him on the other side of the law. Now in prison, he helps the police solve mysteries using a system that invades a person’s identity. Little by little, a trail of blood forms, and it all leads back to his daughter’s murderer.