The manga takes place in 2048 and focuses on Hiryu, a retired Super A-grade Strider who was forced to kill his sister Mariya when she went insane (as seen in the prequel). Hiryu is living a peaceful life in Mongolia when Vice Director Matic convinces him to come out of retirement to save his friend Cain. Cain has been captured in the Kazakh SSR and is a danger to the other Striders. Hiryu, with the help of Strider Sheena, rescues Cain but is attacked by him when he regains consciousness. Sheena dies from her wounds, and Hiryu discovers a device implanted under Cain's neck that has been controlling him - codenamed Zain. Hiryu's sister was also under the influence of Zain. After Cain is freed from the mind-control, he decides to team up with Hiryu to stop the Zain project. They discover that a group known as the "Enterprise" is behind the Zain project, and Vice Director Matic is cooperating with their leader, Faceas Clay. Hiryu, along with Cain and a group of Striders, manages to stop Matic and Clay and destroy the main Zain terminal.
