The character Gyokko, recognized as the Upper Moon Five demon in Demon Slayer, plays a central role in the Swordsmith Village arc alongside the antagonist Hantengu. Their invasion of the Swordsmith Village culminates in a dramatic encounter with Muichiro Tokito, the Mist Hashira, leading to an intense battle that showcases Gyokko’s formidable abilities.
During this confrontation, Gyokko reveals his unique powers, which centralize around aquatic themes and water manipulation. His distinctive obsession with fish has sparked curiosity among fans, and this fixation is rooted in his dark and tragic backstory that shaped him long before he became a demon.
Gyokko’s Origins: A Tragic Past

Before he transformed into the Upper Moon Five demon, Gyokko was known as Managi, a boy from a coastal fishing village. Tragically, his life took a harrowing turn when his parents, who regularly ventured out to sea, drowned during one of their fishing trips. Their bodies eventually washed ashore, leaving a profound imprint on Managi’s psyche.
Confronted with the gruesome sight of his deceased parents, he developed an unsettling fascination with corpses, particularly fish carcasses, reflecting both his grief and the circumstances of his parents’ demise. The villagers, disturbed by Managi’s macabre habits, gradually ostracized him, leading him deeper into isolation.
One fateful day, Managi’s peculiar behavior drew the ire of a local child, who taunted him. In a fit of rage, he murdered the boy and concealed the body within a fish pot. The child’s family uncovered the horrific truth and exacted brutal revenge by stabbing Managi and leaving him to die. However, he was later found by Muzan Kibutsuji, who transformed him into a demon, solidifying his path of darkness.
The Influence of His Past on His Demon Form
Although Gyokko embraced his new demon existence, his memories of suffering fostered an intense hatred for all living beings. His transformation did not extinguish his fixation with fish; rather, it amplified it. Gyokko’s form began to resemble a fish, reflecting his past while utilizing his powers to create grotesque sculptures from the bodies of his victims, often leaving them alive despite their extensive injuries.
Conclusion: The Complexity of Gyokko’s Character
Gyokko showcased remarkable power with his aquatic-based abilities, effectively challenging the Hashira. However, his pride ultimately led to his downfall, as Muichiro Tokito successfully provoked him into defeat. Gyokko’s enduring obsession with the aquatic world serves as a reflection of his tragic human past, a common theme seen with many demons, particularly the Upper Moon ranks, whose powers often mirror their previous experiences.