A candidate for the next head of the Zenin family. He is the son of Zenin Naobito, the cousin of Fushiguro Toji, the older cousin of Zenin Maki and Zenin Mai, and the first cousin once removed of Fushiguro Megumi. He speaks in a Kyoto dialect. He uses informal speech with Toji, calling him "Toji-kun." He has two-tone hair with greenish-blonde mixed with black, four piercings in his left ear, and eyes that are slightly droopy yet sharp, making him stand out among his relatives. His appearance shifts between a gentle and sharp impression. He seems to enjoy his appearance, having dyed his hair blonde. In the story, he wears student-style clothing consisting of a kimono and hakama layered over a mandarin collar shirt. He has a deeply misogynistic tendency, looking down on women to the point of sexually harassing his cousins Maki and Mai, who are 12 years younger, and claiming that women who do not walk three steps behind him deserve to die. He isn't particularly kind to men either. He openly mocks his cousin Jinichi, who is at least 20 years older, for being ugly, and during his fight with Choso, he remarked that incompetent older brothers who are inferior to their younger siblings should just hang themselves. He holds a very low opinion of anyone he does not acknowledge, including family and relatives. Despite his trashy personality, he calls those around him somewhat familiarly by adding "-kun" or "-chan" to their names. Even as an adult, he calls his father Naobito "Papa," showing a surprisingly childish side for his age. If one ignores the setting, he acts so immaturely that he could be mistaken for being the same age as Maki. Having been raised as the pampered next head of the family, he likely never grew up. This personality seems to stem from the Zenin family's unique culture and values, which view male supremacy and talent as a sorcerer as absolute. Raised as a "genius" with an inherited technique, he lacks consideration and empathy for others, resulting in an impolite and arrogant personality. While he is incredibly insolent, he exceptionally admires and views his cousin Fushiguro Toji as an ideal role model. As a child, he went to see Toji intending to look down on him for having no cursed energy despite being a man, but he changed his mind upon witnessing Toji's overwhelming presence and skill. Since then, he has used the "strength" Toji displayed as his own standard. Since childhood, he has perceived himself as the rightful head of the family, repeatedly making remarks and taking attitudes that place others beneath him. He has a strong obsession with success and power, using them to prove his superiority. He does not recognize non-sorcerers or the weak as equal human beings, showing a consistent lack of empathy and arrogance since his first appearance. He has a strong sense of entitlement and demands excessive respect and recognition. He views interpersonal relationships as instrumental and exploitative rather than reciprocal, clearly seen in his blatant disregard for Maki and Mai and his treatment of family members as ranked tools. Taken together, he is a character with narcissistic personality disorder traits, characterized by self-centeredness, grandiosity, and a lack of empathy (arrogant, brazen, and pretentious).