the main character, siwoo lee, lost his parents to a murderer 10 years ago. finally, he meets jack, the killer who killed his parents, and beheads him . “it wasn’t me who killed your parents.” after learning that the real culprit is a ‘contractor’ belonging to a group of killers using superpowers, si-woo lee decides to hunt down the registrants with jack’s help. 킬링킬러