The sub-protagonist of Demon Slayer: Kimetsu no Yaiba. She forms the main quartet (the Kamaboko Squad) along with Tanjiro Kamado, Zenitsu Agatsuma, and Inosuke Hashibira, serving as the sole female member among them.
The younger sister of the protagonist, Tanjiro Kamado. She lived a normal life until one day, she was attacked by Muzan Kibutsuji and turned into a demon. The story begins when Tanjiro embarks on an adventure with Nezuko to turn her back into a human. In essence, she is the catalyst for the story of Demon Slayer: Kimetsu no Yaiba.
During her human life, Tanjiro, as the eldest son, had to spend more than half of his day outside the house to support the family, so Nezuko was almost solely responsible for taking care of her younger siblings. She also did sewing and gathered edible wild plants. Not only did she look after her siblings, but she also willingly helped her mother with household chores, living her life as a filial daughter.
Similar to her brother, she has bangs that reveal her forehead, long hair that reaches past her waist, and drooping eyes with a single strand of hair on the upper eyelash as a focal point, along with pink eyes. In her human past, she had a graceful and mature appearance with black hair tied up with three small ribbons, but after becoming a demon, she wears her hair down, her nails have grown long, she has sharp fangs, her eyes have changed, and she has a slightly youthful appearance due to regression. Even as a human, she was known as a beauty in the village, and given the many mentions of her beauty in the work, it seems her innate beauty remains even after becoming a demon.
Unlike Tanjiro, who strongly resembles their father, Nezuko's facial features, such as her eye shape and the highlights in her eyes, are a perfect match for their mother. In particular, when she was human and her hair was tied up, she looked almost identical to her mother.
She is a considerable beauty, and as mentioned above, her appearance was consistently praised both when she was alive and after becoming a demon. In fact, when Yushiro first saw Nezuko, he called her an 'ugly woman,' but Tanjiro couldn't even comprehend who he was talking about. Considering Tanjiro's personality, who cherishes his family but doesn't speak carelessly, and that Yushiro later changed his words, one can gauge Nezuko's appearance within the story.
Her attire consists of a pink kimono with a hemp leaf pattern, a red and white checkered obi, and a dark brown haori worn over it. After becoming a demon, she folds her kimono to make it easier to move around.
Another of her most prominent features is the bamboo muzzle she wears. Initially, it was placed by Giyu Tomioka as a precaution in case Nezuko went berserk and bit someone. However, Nezuko herself cannot speak anyway and doesn't seem particularly bothered by it, so Tanjiro doesn't say much. Moreover, since she continues to wear it even though she can remove it freely, it might be that Nezuko herself likes it, but it also suggests that she is somewhat aware that she might unintentionally bite someone someday.
In her human life, her father passed away early, so despite the family's poor financial situation, as the eldest daughter responsible for her younger siblings, she was very kind, mature, and self-disciplined. She even advised Tanjiro, saying, 'Happiness isn't just about having plenty,' showing a remarkably precocious personality for her age, even considering the era. Because of this, Tanjiro felt both gratitude and guilt towards Nezuko.
Unfortunately, after becoming a demon, she lost a significant part of her self-awareness. She doesn't consume humans, and her intelligence has regressed to an infantile level. She cannot speak human language and only makes 'mm-hmm' sounds due to the bamboo muzzle. Thanks to Tanjiro, she managed to recall her affection for her family. Later, Urokodaki cast a spell on her, instilling the belief that 'All humans are our family. Do not forgive the demons that harm humans.' Consequently, she is fundamentally friendly towards humans and tries to protect them, and despite being a demon herself, she opposes demons that harm humans. Initially, Tanjiro was uneasy about this, wondering if Urokodaki was disregarding Nezuko's self-awareness by using hypnosis. However, he was relieved when he confirmed Nezuko's self-awareness was intact by observing that she did not antagonize Tamayo and Yushiro, classifying them as 'humans.'
Indeed, possibly due to the effects of regression, she often displays childlike behavior, such as spacing out or acting affectionately towards her brother, in stark contrast to her original mature demeanor. In the Asakusa arc, she sprawled on the floor disrespectfully or occupied herself in a corner while Tanjiro was having a serious conversation with Tamayo. In the Mugen Train arc, she tried to wake her sleeping brother by nudging him with her head, but when he didn't wake up, she headbutted him. Then, when she started bleeding from her head, she cried and threw a tantrum. It seems she was quite adored by Shinobu, Kanao, and Aoi even when she was a demon.
Tamayo speculated that since it's impossible for a demon to have no self-awareness at all, Nezuko's regression might be due to something that takes precedence over the reconstruction of her self-awareness, which later proved to be true. Nezuko was altering the properties of her blood herself, prioritizing things like suppressing her appetite, rapid growth, recovering energy through sleep instead of cannibalism, and liberation from Muzan's interference. In other words, Nezuko's regression occurred because, in the process of being reborn as a demon, she gained a certain degree of self-awareness through her brother before her demonic consciousness was fundamentally formed. Even before that self-awareness was properly formed, she unconsciously prioritized evolution in a way that would benefit her brother and herself.
She has never consumed a single piece of human flesh or a drop of blood, yet she is far stronger than most demons. When Tanjiro fought a demon on his first mission, he thought the demon was inferior to Nezuko because the demon had received a large amount of blood from Muzan. While this was just the demon's speculation at the time, it was later revealed that Muzan had indeed injected her with a large amount of blood. The reason for injecting so much blood was to create a demon that could overcome the sun. Normally, consuming such a large amount of blood would cause the body to collapse before even becoming a demon, but Nezuko, possessing extraordinary talent, endured it and became a powerful demon.
Although she was often at a disadvantage in the early stages due to lack of experience, in the later stages, after gaining experience, she could fight on par with Upper Moons. Urokodaki, Tanjiro's master, emphasized that she was not weak enough to need protection. Gyutaro, the Upper Moon 6, was astonished, sensing a demonic aura comparable to that of an Upper Moon. In the latter half, Kokushibo mentioned that it takes longer for stronger individuals to become demons. In contrast, the man who became a demon in Asakusa showed immediate reactions after receiving blood and became a demon, while Nezuko transformed into a demon the night before Tanjiro discovered her and descended the mountain, suggesting Nezuko's great potential. Later developments revealed that Muzan had indeed injected her with a particularly large amount of blood, suggesting that Nezuko's strength is likely a synergy of her strong will and the large amount of Muzan's blood.
Perhaps due to receiving a particularly large amount of Muzan's blood, she possesses insane specs, at least at the level of Lower Moons, despite never having consumed humans. In the early stages, she had only been a demon for a short time, was focused on the aforementioned property changes, and lacked experience, so she was only considered strong among ordinary demons. However, she soon mastered her Blood Demon Art and began to grow in combat power, eventually achieving what neither Muzan nor the Upper Moons could: overcoming the sun.
Her combat style relies on simple physical attacks, particularly focusing on kicks, combined with her remarkable regenerative abilities. Unlike other demons, she rarely uses her Blood Demon Art because using too much blood causes her to fall asleep. Furthermore, when her stamina depleted due to prolonged battles, she was prone to succumbing to the urge to eat humans and attack them, showing weakness in prolonged fights. However, as mentioned above, even considering these weaknesses, her overwhelming physical specs ensure sufficient combat power.
However, it is certain that she is weaker than almost all Hashira. If she had fought against the top Upper Moons in the final arc, she would have been easily defeated. Nevertheless, with her considerable combat power and unique Blood Demon Art, she had saved Tanjiro multiple times. Moreover, due to the nature of her abilities, she could have been highly effective in the fight against Doma, but she was unable to participate in the final battle due to the plot.
She also has the ability to change her body size. Normally, she shrinks her body to a childlike size to rest inside a box, but when fighting, she enlarges her body to be even bigger than usual.
As a result of her evolution, which replaced cannibalism with sleep, she can survive without consuming humans at all. Demons must consume people before they can become stronger and survive. Even Tamayo and Yushiro, who modified their bodies, must consume blood and thus keep it stored separately. However, Nezuko suppresses her cannibalistic urges solely through sleep and instead accumulates strength and grows stronger. Considering that most of the tragedies in this work stem from the demonic urge to consume humans, this is an extremely unusual feat.
Blood Demon Art: "Explosive Blood" (爆血 - Bakuketsu): She generates flames that burn only demons through her blood. These flames not only burn the demon's body but also burn and weaken the regenerative abilities of Blood Demon Arts that act through blood or flesh. She can also burn and nullify demonic poisons if they function as Blood Demon Arts. Of course, since it only burns and heals parts of the demon, when she healed Tengen Uzui, she detoxified the demonic poison but could not heal the injuries sustained in battle.
Conversely, it is harmless to humans and other objects, and does not burn surrounding materials like clothing at all.
Although it is a considerably powerful ability, using it actively requires her to shed her own blood, which consumes a lot of stamina, so she doesn't use it frequently. However, as Nezuko gradually grew stronger as a demon, the frequency of its use increased. While she used it briefly to wake her companions in the Mugen Train arc, she used it without concern for stamina consumption in the Entertainment District arc and Swordsmith Village arc, where her Demon Slayer Mark had appeared.
This was also the first line Nezuko spoke after becoming a demon. In the anime, it is depicted in crimson and pink to distinguish it from Tanjiro's Hinokami Kagura.
Furthermore, reflecting its property of burning demons, despite being a Blood Demon Art that utilizes demonic blood, it is not affected by the Nichirin Blade.