Nezuko Kamado/Relationships

Tanjiro Kamado
Tanjiro is the elder brother of Nezuko and her only remaining family member alive after her family was killed. As such, Nezuko, who is usually calm and well-mannered, will become enraged and attack any Demon who harms Tanjiro. Being the sole surviving members of a poor family, the siblings are very close, trusting and loving of one another. He is likely the only one capable of actively calming Nezuko down by calling her name or singing to her their mother's lullaby.

After Muzan turns Tanjiro into a Demon, Nezuko is the only person who he does not try to kill or purposefully harm, even after she clings to him and blocks one of his attacks.

Zenitsu Agatsuma
Upon seeing her for the first time, Zenitsu falls in love with Nezuko at first sight. She apparently views Zenitsu as a "weird dandelion" and does not seem to reciprocate his feelings. Although the two are rarely seen interacting together, Zenitsu treats her with affection and care.

Despite his cowardly nature, Zenitsu musters the courage to ascend to Natagumo Mountain upon realizing that Tanjiro (and by proxy Nezuko) were in the territory of the Spider Family, intending to protect Nezuko. During their recovery training, Zenitsu would sit beside her box and tell her stories about Tanjiro and their rehabilitation training. Nezuko would often respond by moving and scratching her box, suggesting that she enjoyed listening to Zenitsu's stories.

As Nezuko returns to humanity, she starts to remember her time as a Demon and in particular a memory of Zenitsu gifting her flowers, hinting she does see him in a good light.

After the taisho period, Nezuko and Zenitsu have great grandchildren living in tokyo. Meaning that they got married during the taisho period.

Sakonji Urokodaki
When Giyu tells his master Sakonji about Tanjiro and his demonized sister along with his belief that the two were different, Sakonji takes in Tanjiro as a disciple while allowing Nezuko to rest in his house. Thought the two do not have too much interaction, the two seem to care for each other. To ensure Nezuko would not succumb to her Demon instincts, he did a (rare case of benevolent) brainwashing to convince her that humans were a part of her family and must be protected. When Tanjiro survives the test to become a Demon Slayer and returns, he receives a hug from both Nezuko and Sakonji. Later, Sakonji sends a letter to Kagaya Ubuyashiki, the leader of the Demon Slayer Corps, citing that if Nezuko ever did succumb to her Demon instincts, he would commit suicide for her actions, demonstraing great care for her wellbeing and trust in both her and Tanjiro. After Nezuko takes Tamayo's drug to transform back into a human, Sakonji is the one by her bedside to watch over her.

Giyu Tomioka
When Giyu responds to the murder of the Kamado family, he tries to kill Nezuko since she had recently transformed into a Demon. He captures her and nearly kills her even when Tanjiro begs him to spare her, believing Nezuko to be a threat to humanity as all Demons were. However, he is genuinely surprised when she chooses not to eat her brother but rather protect them instead. Despite his disgust towards Demons, Giyu decides to give her and Tanjiro a chance and sends them to his master Sakonji for training.

While Giyu and Nezuko do not have much further interaction, they both share a deep bond with Tanjiro. In addition, Giyu protects Nezuko from being slain by fellow Demon Slayer Shinobu Kocho and has promised to take responsibility for not slaying Nezuko given his status as Hashira and, should she eventually decide to succumb to her demon instincts and murder someone, he would commit suicide, demonstrating great faith and care for her.

Shinobu Kocho
While the two have rarely interacted, Shinobu appears to care for Nezuko. At first, she tries to kill Nezuko due to her status as a Demon. However, during Nezuko and Tanjiro's trial at the Hashira meeting, Shinobu does seem to feel sorry for the siblings when they are questioned and later shows concern for the two, even allowing them to stay at her mansion and rest. While Shinobu still holds a deep hatred for Demons as a whole, it doesn't seem to extend to Nezuko, partially because she sympathizes with Tanjiro and his kind nature being similar to her sister's. Shinobu also let Nezuko look at her pet goldfish.

Tamayo
Nezuko is seen to be at ease around Tamayo, acting more childish than she would normally. She sees Tamayo the same way she views all humans: a part of her family, specifically an individual similar to her mother. This endears her to Tamayo, as she is touched by the fact that Nezuko views her as a normal person, despite her status as a Demon and her past sins.

Yushiro
At first, Nezuko is threatened by Yushiro's presence as she senses that he is a Demon; however after she realizes he shows no ill intent or harm towards her or Tanjiro, she no longer perceives him as a threat and stops being wary around him.

Yushiro initially sees her as "unsightly," due to his personal belief that all Demons are disgusting and grotesque with the sole exception being Tamayo, his master and the object of his undying love. However, after they fight side-by-side during the attack on their hidden clinic by Yahaba and Susamaru, he revises his opinion of her, calling her beautiful. Nezuko likewise sees Yushiro as one of her younger siblings and begins patting his head, much to his dismay.

Mitsuri Kanroji
Nezuko has a close relationship with Mitsuri, first meeting her at the hidden Swordsmith Village. They enjoy each others' company and have a relationship that could be seen as akin to sisters. In a side chapter, it is revealed that Nezuko enjoys getting Tanjiro to style her hair like Mitsuri's.

Kanao Tsuyuri
While they have little to no interaction in the series, Nezuko cares enough for Kanao that she was distraught when Tanjiro (now a demon influenced by Muzan) injured Kanao and referred to her as Kanao chan, implying there are some closeness between them.