Niragi is a tall and slim man with pale skin and shoulder-length black hair that is put into a half-up topknot. He has silver piercings in his left eyebrow, left nostril, and his tongue, and wears a black and white giraffe print button-up shirt, black leather pants and black heeled ankle shoes. He is often seen carrying a rifle against his shoulder. One of his unique features is his habit of sticking out his pierced tongue, mostly in a manner that makes others uncomfortable.
After the events of the Ten of Hearts game, Niragi sustained severe, second- and third-degree burns all over his face and upper body. His hair is now short and choppy, and his left eyebrow is missing entirely. He wears bandages that cover his arms, legs, and upper body that progressively become blackened with presumably dried blood as time passes. On top of the bandages he wears a grey snake print button-up shirt with mid-length sleeves and dark blue capris. Underneath his bandages he wears a thick grey sweater. He initially uses his tattered giraffe print shirt as a makeshift turban to cover half of his face, but abandons it after the King of Clubs game.
Niragi is portrayed as a young yet dangerous militant member of the Beach. He generally displays volatile and aggressive behavior and uses means of violence, intimidation, and psychological torture to achieve his goals. While content with taking orders from and submitting to the leadership of his captain, Aguni, he relishes in the power his second-in-command position grants him and abuses it with little to no concern for the lives or well-being of others.
His unstable and erratic nature is the result of childhood trauma caused by severe bullying during his school years. Due to his experiences in the real world, Niragi grew to believe humanity to be inherently evil and began using the dystopian and lawless state of the Borderlands to satisfy his hunger for the power and status he lacks in the real world. His initially manic and exaggerated demeanor, with which he carried himself at the Beach as Aguni's second in command, becomes greatly reduced after he sustains debilitating injuries and loses his position of power with the collapse of the Beach, now displaying a calmer, although more cynical and nihilistic attitude. However, even Niragi has a sliver of humanity: after Tatta's sacrifice saved the group, he stays behind to watch his funeral and pay his respects, admitting he is grateful to him for saving his life.
At his core, Niragi is a deeply lonely and embittered person desperate to find mutual ground with those he deems to be alike to him, namely Arisu and Chishiya, who he claims are at their core as selfish and outcast as he is. He seeks to corrupt the spirits of those who hold onto the hope and ideals he long abandoned, instead choosing to spread the pain and suffering he himself was subjected to in his past, and become a hated and despised person on his own accord. When being faced with his deplorable actions, Niragi deflects from them and instead chooses to blame the world around him for his misdeeds, rather than holding himself accountable. However, after Arisu refuses to play his game and instead saves his life again, crushing his ideals, Niragi decides to return back to the real world rather than die and go to hell as he initially planned, seemingly choosing to give life a second chance.
Due to his initially timid personality and plain looks, Niragi was a victim of severe bullying and physical harassment. In a flashback of his past, he was seen being held down by a group of five male students and having his body used as a target for baseball practice. It was stated that he had been force-fed rice mixed with urine on at least one occasion, as the bullies threatened to repeat this action if he did not hold still while the baseballs were hitting him in the face. At some point, presumably after graduation, he went through a series of extreme changes to his appearance and personality in order to protect himself from further abuse.