In the opening chapters, Mido Sayoko, a self-deprecating high school student, is abruptly pulled from sleep by a small, fairy-like avatar. This being, Kyoka Kuribayashi, claims to be a human university student from the 27th-century "United States Northern," explaining that Sayoko has been chosen for a "match" as part of Kyoka's academic test and a TV show. Sayoko's assigned ability is "Nothing," which Kyoka dismisses as a "dud," leading Sayoko to sarcastically name it "Scar."
Sayoko is then transported to a deserted concrete factory, where a male announcer declares a death match between "A-side Grasshopper" and "B-side Scar" (Sayoko). Sayoko, initially convinced it's a dream, watches her opponent, a high school girl named Grasshopper, repeatedly test her ability to jump to immense heights and cause destructive impacts. Sayoko quickly realizes this is a real death game, and she is utterly powerless.
Grasshopper confronts Sayoko, confirming their roles before attempting to crush her with a powerful jump. Sayoko, despite her lack of athleticism, instinctively evades, initiating a desperate chase. Grasshopper, rapidly mastering her ability, aims to kill. Sayoko's flight leads her to a bone aggregate storage area. In a twist of fate, Grasshopper, attempting to land in Sayoko's path, slips on the roof and falls into a sand pile. Her ability's protective force field, which required a specific jump-and-fall sequence, fails, leaving her buried and disoriented. Sayoko seizes the chance to hide in an unlocked mixer truck. From her hiding spot, she watches Grasshopper climb to the plant roof to search, only to slip again and fall to her gruesome death. The announcer declares Sayoko the winner, much to her horror, before she is transported back to her bed, convinced it was a terrible, mentally exhausting dream.
Concurrently, another match concludes in a suburban parking lot, where a male student, Light Blade, has used his plasma sword ability to gruesomely kill his opponent. Despite severe injuries, Light Blade is ecstatic, having found a sense of purpose and excitement in the deadly game, fulfilling his supervisor Militza's implied goal of giving meaning to his "worthless" existence.
The next day, Sayoko returns to her mundane life, her thoughts consumed by her beautiful and popular childhood friend, Nagano Erika, whom she idolizes as a "goddess." Sayoko, an underachiever with deep insecurities, believes she is unworthy of Erika and passively endures daily bullying from a classmate, Nakata Himeko, to avoid drawing attention that might worry Erika. Sayoko's internal monologue reveals her obsessive love for Erika, her self-loathing, and her dread of the day they will inevitably separate, believing her life has no meaning beyond Erika.
However, Sayoko's fragile reality shatters when Kyoka reappears in her room, confirming the matches are real. Kyoka excitedly explains Grasshopper's ability failure and her own academic success due to Sayoko's win, further detailing the future world's history of nuclear wars and the matches being part of a university test and a TV show. Sayoko initially believes she's gone insane, but Kyoka's persistence forces her to accept the terrifying truth: she is a participant in a deadly, futuristic game, and her life, and perhaps Erika's, is now inextricably linked to this brutal reality.
