Yes, I’m one of those numerous Avatar fans who strongly believes that Zuko and Katara should have been a couple at the end of Avatar: The Last Airbender, rather than Aang and Katara. After all, there is clear foreshadowing for a romantic relationship between them, despite the series not going in that direction in the end. Here are some reasons for why so many believe Zutara (a term used within the fandom to refer to a romantic relationship between Zuko and Katara) was meant to be.
Firstly, some of the scenes between Zuko and Katara were scenes that you would expect to see between two characters who are romantically interested in each other. Think about the scene at the end of season two where Katara offers to heal Zuko’s scar. She is shown placing her hand on his face, an intimate gesture, and then Aang rushes in, hugging Katara while giving Zuko a jealous look. If someone who has never seen the show before saw this scene out of context, it would seem to them like a love triangle was brewing.
There is also the episode where Zuko and Katara track down the man responsible for the death of Katara’s mother. This episode escalates what looks like romantic tension between the two characters. For instance, Zuko and Katara have an argument about trust, and Zuko stays up all night outside of Katara’s tent because he’s determined to gain her trust. This feels like the way that two people who are romantically involved might interact with each other.
And what about the finale, in which Zuko jumps in front of lightning to save Katara? If that isn’t romantically coded, then I’m not sure what is! After seeing that, it was very strange to see Aang and Katara, as well as Zuko and Mai, get together in the end. It felt as though Zuko saving Katara was an action that would lead to them realizing their feelings for each other. The series contained so much buildup towards a potential relationship between Zuko and Katara, with this climactic scene between the two of them occurring right at the end, but then nothing came of it.
There have also been much smaller hints in the series that Zuko and Katara were going to become a couple in the end. For example, June makes more than one comment about Katara being Zuko’s girlfriend, and the Ember Island play features Zuko and Katara as a couple. In this way, the series is acknowledging that Zutara has been foreshadowed and is something that should be acknowledged somehow. This shows that the romantic tension between them is not just in our imaginations – it’s also being noticed by other characters.
In addition, Zuko and Katara have very personal interactions in this series, which helps to provide setup for an eventual relationship. For example, at the end of season one, when Zuko and Katara fight, the fight seems personal somehow. Zuko seems truly angry at Katara in a way that he hasn’t been with Aang before, aiming many angry and insulting remarks at her. Zuko can see for himself how quickly Katara has mastered waterbending, and perhaps this reminds him of how naturally gifted Azula is at her own bending discipline and how much better she is than him at firebending. This must have conjured up feelings of inferiority in Zuko, leading to his anger and to their fight being more personal. Moreover, they both bond over losing their mothers to the Fire Nation, and this allows Zuko to connect with Katara in a way that he doesn’t connect with anyone else. Katara is the only person that we ever see Zuko discuss his mother with (other than Ozai, but that doesn’t count). All of this helps to build tension between Zuko and Katara.
So, those were the reasons why I think Zuko and Katara were meant to be together. The show dropped plenty of hints and foreshadowing related to Zutara, and that’s why so many fans of Avatar: The Last Airbender are also huge fans of Zuko and Katara ending up together.