NezuTan

"The bond between Nezuko and I can't be severed, not by anyone!"

- Tanjiro to Rui, Episode 19

NezuTan is the familyship between Tanjiro Kamado and Nezuko Kamado from the Demon Slayer fandom.

Volumes 1-3
Tanjiro and Nezuko are the surviving members of a family of seven. Nezuko was transformed into a demon after their household was attacked by the First Demon, Muzan, when Tanjiro came back the morning the massacre happened, he found only Nezuko still alive. He then tries to carry her to the nearest village in an attempt to find a doctor and save Nezuko.

On his way there, Nezuko "woke up" as a demon, she tries to attack her brother but after some struggling, starts crying as Tanjiro begs her to hang in there, to not give in to the "demon". Giyuu arrives to save Tanjiro from Nezuko but Tanjiro pushes Nezuko out the way instead and protects her.

Giyuu gets a hold on Nezuko anyway and stabs her shoulder, causing Tanjiro to cry and beg Giyuu on his hands and knees to spare his little sister. Giyuu berates Tanjiro for being so weak and tells him that if he wants to protect his sister, then he'll have to fight for her. Which Tanjiro does - he charges Giyuu with the ax he had, but even though he got knocked out in the process, he nearly landed a blow on the demon slayer after he went down, the diversion gave Nezuko the opportunity to get out of Giyuu's hold. However, despite her starved state, Nezuko didn't eat her brother and instead tried to protect him from Giyuu.

Tanjiro wakes to find Nezuko unconscious and with a bamboo muzzle. He is relieved that Giyuu didn't end up killing Nezuko, and leads her back to where their family was killed to pay their respects, now that he knows Nezuko doesn't need a doctor. When Tanjiro returns from Final Selection, he finds that Nezuko has awakened and was waiting for him. Tanjiro stumbles from his exhaustion, but Nezuko runs over and embraces him. Tanjiro reciprocates and starts crying as he tells Nezuko how he was so worried about her, and that she was asleep for so long that he was afraid she would go. Following their reunion, Urokodaki reveals that he's created a special box for Tanjiro to carry Nezuko in, so that they can still be together throughout their journey.

At the Demon Slaying Corps Headquarters, the first thing Tanjiro asks for once he wakes up is Nezuko and that where she was. Sanemi then appears and is holding the box that Nezuko is in, and stabs her in front of Tanjiro, causing him to angrily and recklessly charge the Wind Pillar and headbutt him.

Fanon
The reaction to their relationship and closeness is largely positive by the fandom. As the entire story is about Tanjiro turning his sister back into a human and avenging their family, fans have praised how heart-touching their relationship is, especially Tanjiro's determination to save his little sister. Fanworks often feature the two with the rest of their deceased family, "reunited" seems to a common theme.

There are some fans who ship them romantically, but it is generally frowned upon due to the fact they are blood siblings.

Fandom
NO

Trivia

 * Nezuko is 14 while Tanjiro is 15 years old.
 * Tanjiro is the only one who can calm Nezuko down by calling her name or singing their mother's lullaby.