Tooru Souma is a hacker in the group Steppenwolf, which earns its living by breaking into servers and selling what it finds. On the group's last job before disbanding, they hack into what turns out to be a military honeypot — a trap baited for terrorists. Most of Steppenwolf is arrested. One of Tooru's friends is killed by an unknown Simulacrum. To investigate the death and get justice, Tooru accepts an offer to join the military itself.