Nobunaga Hazama is a member of the Phantom Troupe, a notorious group of thieves. He was born in the slums of Ryuseigai and has been with the Troupe since its early days. His closest friend within the group is Uvogin; the two are said to bring out the best in each other during combat. Nobunaga is a skilled swordsman who fights with a long Japanese sword. He uses Nen to enhance his swordplay, and his specialty is En, which he extends in a circular boundary around himself. According to descriptions, his En reaches about four meters, and once an opponent steps inside it, he can retaliate immediately. Because of his reliance on this technique, Franklin has called him the "King of Carelessness."

Personality-wise, Nobunaga is typically calm and composed, but he can be bold and even confrontational with other Troupe members when provoked. Unlike some of his comrades, he displays a surprisingly friendly and approachable side. When he first meets Gon Freecss and Killua Zoldyck during the Yorknew City arc, he smiles at them frequently, expresses a desire to be friends, and even asks Chrollo Lucilfer to consider making the two boys Troupe members. This openness stems from his seeing a resemblance between Gon and Uvogin, which fuels his interest in recruiting them.

During the Greed Island arc, the Phantom Troupe enters the game to find an exorcist who can remove the Judgement Chain that Kurapika placed on Chrollo, which prevents him from using Nen. Nobunaga accompanies the group on this mission. His role in this arc is primarily as a supporting antagonist who interacts with Gon and Killua but does not engage in major combat against them. He warns Killua about the gap in their abilities, but Killua ignores the advice. Nobunaga ultimately leaves Greed Island with the other Troupe members after Chrollo’s Nen is restored.

Nobunaga’s motivations are tied to his loyalty to the Troupe and his personal sense of camaraderie. He values the group’s survival and the well-being of its members, especially Chrollo and the memory of Uvogin. His character does not undergo significant development in the Greed Island arc itself, but his earlier interactions in Yorknew City and his behavior during the arc reinforce his mix of lethal professionalism and surprising warmth. His notable abilities include his swordsmanship, which he uses with great skill, and his mastery of En for detection and combat. He is an Enhancer-type Nen user, though his full Hatsu has not been revealed in the anime or manga within the Greed Island portion of the story.