Naoya Zenin is a Special Grade 1 Jujutsu Sorcerer and the youngest son of Naobito Zenin, the former head of the Zenin clan, one of the three great jujutsu families. He was raised within the clan’s rigid and deeply traditional environment, where inherited cursed techniques and birthright determined status. From a young age, Naoya displayed exceptional talent and inherited his father’s prized cursed technique, Projection Sorcery, which positioned him as the favored heir and cultivated an inflated sense of superiority. His upbringing instilled in him the clan’s most toxic values, including a profound misogyny and a belief that those without cursed energy or who did not conform to the clan’s standards were inferior and unworthy of respect.

Naoya’s personality is defined by extreme arrogance, narcissism, and a cruel, condescending demeanor. He views himself as the rightful successor to the clan headship and measures worth almost exclusively by strength, birthright, and adherence to tradition. He holds particular contempt for his cousin Maki Zenin, whom he regards as an embarrassment for pursuing strength despite being born without cursed energy. His misogynistic worldview leads him to dismiss women as inherently subordinate, and he speaks to and about them with open disdain. Despite his overconfidence, Naoya harbors a complicated fixation on Toji Fushiguro, a man who abandoned the Zenin clan and achieved legendary power through a heavenly restriction that granted immense physical ability at the cost of all cursed energy. Naoya both admires Toji’s dominance and resents the freedom Toji represents, exposing a deep insecurity beneath his bravado.

Naoya’s primary motivation is to become the head of the Zenin clan. When Naobito dies during the Shibuya Incident, a previously established will names Megumi Fushiguro as the next clan head, because Megumi inherited the Ten Shadows Technique, the clan’s most valued inherited ability, and because Gojo Satoru had been sealed. This decision enrages Naoya, who believes the position is his by birthright. He resolves to kill Megumi and anyone who protects him, viewing Megumi as an outsider unworthy of the title. His desire for power and validation drives nearly every action he takes in the Culling Game arc.

In the Culling Game arc, Naoya first appears during the aftermath of the Shibuya Incident as the jujutsu world descends into chaos. He actively participates in the hunt for Yuji Itadori and attempts to ambush him and Choso to draw out Megumi. He engages in combat with Choso, using his superior speed and Projection Sorcery to gain the upper hand initially, but his overconfidence leads to setbacks. His role expands significantly when Maki Zenin returns to the Zenin compound to claim cursed tools. Naoya confronts her there with the same arrogance he has always shown, refusing to acknowledge her growth. This confrontation culminates in a brutal battle where Maki, having shed her limitations, defeats him decisively. Naoya is left alive but gravely wounded and is later killed by Maki’s mother. His intense hatred and unresolved ambition prevent him from passing on peacefully, and he reincarnates as a vengeful curse during the Culling Game itself.

Key relationships define Naoya’s storyline. His relationship with Maki Zenin is one of pure antagonism; he dismisses her as weak and inferior, and her eventual triumph over him represents the collapse of the old Zenin order he embodies. His feelings toward Toji Fushiguro are more complex, mixing respect for his strength with resentment toward his rejection of clan authority. Naoya’s father, Naobito, shaped his worldview, and his fixation on inheriting his father’s technique and position is central to his identity. His rivalry with Megumi Fushiguro is driven by jealousy and a sense of entitlement, as Megumi’s existence threatens Naoya’s claim to leadership.

Naoya’s development is marked by his inability to change. He remains entrenched in his beliefs even in the face of overwhelming defeat. His death does not bring redemption or reflection; instead, his hatred intensifies, and his transformation into a vengeful curse demonstrates how completely his ego and resentment consume him. In his cursed form, he becomes even more powerful and relentless, but his core motivations remain unchanged. He is ultimately defeated by Maki again, this time permanently, solidifying the end of the Zenin clan’s traditionalist legacy.

Naoya’s most notable ability is Projection Sorcery, an inherited Zenin clan technique. This technique allows him to divide one second into twenty-four distinct frames and pre-program a sequence of up to twenty-four movements within that timeframe. By following this predetermined path, he can move at phenomenal, near-subsonic speeds. Additionally, any person or object he touches with his palm must also obey the same twenty-four-frame rule or be frozen in place for a full second, creating openings for attack. Naoya is a master hand-to-hand combatant who relies on jujutsu and speed rather than weapons, though he does keep a hidden knife for emergencies. After his rebirth as a vengeful curse, his physical form changes dramatically, granting him flight, rapid regeneration, and even greater speed that surpasses the limits he had as a human. He also gains the ability to extend tendrils from his body for attack and mobility, and his cursed technique becomes more versatile. His cursed spirit form retains the Projection Sorcery ability, now amplified, and he gains access to a domain expansion, which traps opponents in a space governed by the twenty-four-frame rule. However, his domain has a critical weakness: it cannot target beings with no cursed energy, which ultimately allows Maki to overcome him.