This pairing comes from Avatar: The Last Airbender and was the pairing of Zuko and Katara. It was one of the popular pairings whose "rival"pairing was Kataang . While there was less in-your-face evidence to support this shipping fans still produced evidence and cited reasons that it was and should be possible.
At first the two characters did not get along as they were on seperate sides - he was attempting to capture Aang, while Katara was trying to help Aang fulfill his destiny and avoid capture. However as the program went on the two characters eventually were able to stand on common ground and put aside their enemity. They fought together as a pair and were able to trust in each other.
The relationship never turned canon.