Kyo Sogoru is a high school student and enthusiastic swim team member with a trained athletic physique, maintaining good academics. His personality is reckless and impulsive, prone to frustration when confused, a sharp contrast to his past thoughtful, prudent nature where he internalized pain. This shift resulted from "wet damage." His current existence is a reconstructed digital entity formed from residual data fragments called the "phantom body buffer," residing in the simulated Maihama server. This reconstruction caused significant memory loss regarding his original identity, relationships, and past. He previously died battling the Gards-orm on the moon server via self-destruction. Before that death, he shared a close relationship with Shizuno Misaki (Yehl), known since elementary school and potentially idolized. He deliberately left warnings for his reconstructed self against involvement with Shizuno to prevent recurring emotional exhaustion. Upon encountering Shizuno again, Kyo awakens as a Celebrant, gaining perception of reality's true nature. Despite memory loss, he demonstrates innate proficiency as the Gunner pilot of the mecha Zegapain Altair. Through ongoing battles, he gradually discovers his world is a digital construct within quantum servers preserving humanity after the real world's destruction. Initial despair gives way to resolve to protect the Maihama server and its inhabitants. During this journey, he develops romantic feelings for childhood friend Ryoko Kaminagi and vows to protect her. Fragmented memories resurface via combat and interactions, revealing his former self and past connection to Shizuno. Ultimately, Kyo uses the Resurrection System to regain a physical biological body, becoming the only individual to achieve this. This restoration fully integrates his thoughtful past self and passionate reconstructed self, recovering all lost memories. He retains affection for both Ryoko and Shizuno. Following the final conflict, he dedicates himself to constructing a new Resurrection System on Earth in the physical world. His catchphrase is "It's impossible!" Key relationships include conflict and reconciliation with friend Kenta Kawaguchi, leadership within the swim team, and interactions with Celebrant allies Shima and Minato aboard the Oceanus command vessel.