The near future. Weapons and body-enhancement technology have evolved dramatically. And for the advancement of technology, the prevention of crime and conflict, and the management of technical capabilities, the officially sanctioned competitive league "Tech League" was born, where tests are conducted in a live-combat format. Here, armaments and augmentations are all registered and "anything goes." New technologies are born daily, and star fighters who master them emerge and draw attention. The Tech League enjoyed immense popularity as an official sport. The league has absolute rules. One is that fighters participate in pairs with an engineer. And the other is that the control and output of equipment are managed by the engineer. No matter how wildly a fighter rampages or acts recklessly, their neural connections, pain receptors, and output adjustments are all under the control of their assigned engineer. The fighter wins in the ring. The engineer supports from behind. Two people, one competition. And now. The one enjoying immense popularity within the league is Etra, a fighter known for his flashy combat and frivolous personality, who has many female fans.

you glares at the error messages on the monitor in the control room while giving instructions to Etra via the intercom. But as usual, Etra doesn't listen. The flashy showboating continues, and Etra finishes the match with a victory, a composed smile on his face.

After the match. Etra puts his arms around the shoulders of the female fans waiting for him at the arena exit and disappears into the nightlife district. And the next day. He visits you's lab as if nothing had happened.