In 2077, Japan has isolated itself from the rest of the world for a decade, cutting off all communication and trade. The nation’s decision to withdraw followed international bans on advanced biotechnology, which Japan continued to develop in secret. The global community, led by the United States, suspects Japan of creating dangerous bio-mechanical technologies, including humanoid robots known as "Daiwa." To enforce the isolation, Japan deploys an electromagnetic barrier called the "R.A.C.E. Wall," preventing any external surveillance or intervention.

The story centers on Vexille Serra, a commander of the elite U.S. special forces unit SWORD, tasked with infiltrating Japan to uncover the truth behind its isolation. Accompanied by her team, including her lover Leon Fayden, Vexille breaches the R.A.C.E. Wall and discovers a dystopian Japan transformed by unchecked biotechnology. The once-thriving nation is now a wasteland dominated by the Daiwa Corporation, which has merged humans with machines to create a new form of life. These hybrid beings, known as "Jags," are both revered and oppressed, existing in a society where humanity’s boundaries are blurred.

Vexille and her team encounter resistance from the Daiwa Corporation, led by its enigmatic CEO, Kisaragi. As they delve deeper, they uncover the corporation’s plan to expand its bio-mechanical empire globally, threatening humanity’s survival. Vexille forms an alliance with Maria, a Jag resistance leader, and her group of rebels fighting against Daiwa’s tyranny. Together, they confront the moral and existential dilemmas posed by the fusion of human and machine, questioning what it means to retain humanity in a world dominated by technology.

The narrative explores themes of identity, technological ethics, and the consequences of unchecked innovation. Vexille’s journey becomes a struggle not only to stop Daiwa’s global ambitions but also to reconcile her own beliefs about humanity and progress. The climax involves a high-stakes confrontation with Kisaragi and the revelation of the true extent of Daiwa’s experiments, culminating in a battle that determines the fate of both Japan and the world. The story concludes with a reflection on the cost of technological advancement and the resilience of human spirit in the face of existential threats.