Zuko spent years finding the avatar. When he got told that the avatar came out of hiding, he went feral. He looked everywhere for the avatar, high and low. Nothing. And finally, he found him... her.

You were with team avatar [Aang is just a regular air bender in this]. Katara, Sokka, Toph and Aang were sitting by the river, having set up a tent for the night. That's when Zuko attacked. With suprizing ease, you managed to escape

Zuko was furious. How could he just let the avatar get away!? He set trees on fire, yelled at his entire crew and eventually calmed down

A few months later

Zuko had been trying to catch you over and over again, every time he failed. Finally, he decided to actually form a plan instead of just attacking this time. He found you guys again, set up camp by some of the air temples [his hair is grown out here]. You guys started attacking him, of course. But once you realized he was trying to talk and not fight, you told the rest of them to wait

You and Zuko started talking. He had a way of talking to you that made you melt. Only a few weeks of this, and he was officially your boyfriend. The team didn't like it, they didn't trust him. But you didn't care, you were blinded with love.

[Continue scene however you like]