Nezuko Kamado is the younger sister of Tanjiro Kamado and one of the few survivors of the attack that killed the rest of their family. After being transformed into a demon by Muzan Kibutsuji, she retains her humanity and refuses to consume human flesh, a defiance that sets her apart from all other demons. She wears a bamboo muzzle to prevent herself from biting anyone and communicates primarily through gestures, hums, and expressive facial cues. Her personality remains altruistic and kind, and she displays a fierce protective instinct toward her brother and anyone she considers family. She is motivated by an unwavering desire to protect Tanjiro and to help him in his quest to find a cure for her condition, never wavering in her resolution to harm only demons and spare humans.

During the Entertainment District Arc, Nezuko plays a critical role in the battle against the Upper Rank demons Daki and Gyutaro. Early in the conflict, Daki cuts Nezuko into pieces, but Nezuko rapidly regenerates her body, demonstrating a level of recovery that shocks even her opponent. Under the extreme emotional and physical pressure of the fight, Nezuko awakens a berserk-like transformation known as her Advanced Demon Form. In this state, she takes on a more adult appearance, grows a single horn on the right side of her forehead, and develops vine-like markings across her body. Her physical strength increases dramatically, allowing her to overpower Daki and toss her around with ease. However, this transformation also pushes her closer to her demonic instincts. For a brief time, she loses her muzzle and nearly attacks a human. Tanjiro calms her by singing a lullaby their mother used to sing, bringing her back to her senses. Later in the arc, after Gyutaro is defeated and his poison threatens to kill Tanjiro, Tengen Uzui, and Inosuke Hashibira, Nezuko uses her Blood Demon Art, Exploding Blood, to burn the lethal poison out of their bloodstreams, saving their lives. Her flames are unique in that they harm only demons and demonic substances while remaining completely harmless to humans.

Nezuko’s key relationship is with her brother Tanjiro, who serves as both her protector and her anchor to her humanity. She also shares a bond with Zenitsu Agatsuma, who is deeply infatuated with her, and with Inosuke Hashibira, who respects her strength. Her role in the story during this arc is that of a powerful ally and a catalyst for key turning points in the battle, as her awakening and her healing flames directly affect the outcome.

In terms of notable abilities, Nezuko possesses superhuman strength, speed, and endurance. She can alter her body size at will, shrinking to fit into the box Tanjiro carries or growing larger for combat. She regenerates from severe wounds and lost limbs rapidly and does not need to eat humans to regain her strength; instead, she recovers through sleep. Her Blood Demon Art, Exploding Blood, allows her to ignite her own blood into pink flames that burn demons and inhibit their regeneration. She also uses this ability to purify demon poison from human bodies, a feat that proves decisive in the Entertainment District. Furthermore, Nezuko demonstrates a remarkable growth rate, becoming more powerful over time without consuming human blood. Her development in this arc represents a significant step in her journey, as she learns to control her awakened form and deepens her commitment to protecting humans, even at the cost of nearly losing herself.