Yuya Kanzaki, a 15-year-old transfer student at Aiko Tachibana's school, exhibits a mature and aloof demeanor incongruent with his age. His surname blends the kanji for "god" (神) and "cape/peninsula" (崎), while "Yuya" merges "hero, manly" (雄) and "how/alas" (哉). He confronts Aiko with critical revelations: her body is artificial, her original form and family are imprisoned at the Burst's epicenter (Primary Point), and only she can halt the Burst incident. This knowledge originates from his true identity as Dr. Toshihide Yura, a deceased lead Kiryu Biotech researcher from the initial Burst event. His brain, salvaged by colleague Susumu Kurose, was implanted into an artificial organism designated "Unit One" or "Duplicate One," explaining his youthful appearance. Guiding the team covertly to Primary Point, Yuya conceals his identity while pursuing his objective: terminating the Burst he unintentionally caused, motivated by responsibility and atonement. He maintains a stoic, emotionally reserved facade, rarely shifting expressions and keeping psychological distance. Trust requires substantial effort to breach his defenses. During the mission, he clashes with Dr. Kyōsuke Isazu, who aims to exploit the Malignant Matter to revive his comatose daughter Yuzuha. The conflict intensifies when Isazu links to Yuzuha's neural network within the Matter, destabilizing it and risking the Burst's expansion. Yuya sacrifices himself to halt Isazu and stabilize the network, enabling Aiko to reverse the Burst. Post-mission, he vanishes without reuniting with Aiko but ensures her artificial body gains autonomy for independent life. Physically, he possesses black hair, blue eyes, a 5'8" stature, and bears scars likely tied to his transformation.