On the morning of Coronation Day, Zuko rose before dawn. He dressed in his royal regalia and went to the Agni that was part of the palace complex. As he and Katara knelt in front of the sacred hearth, the Fire Sages chanted blessings over them. They rose and repeated their vow to tend Agni's holy flame and work for the honor and glory of the Fire Nation as long as life burned within them. This august burden weighed heavily on Zuko's shoulders. Katara smiled at him and clasped his hand. The burden halved.
The Head Sage placed a golden flame in Zuko's topknot. Katara knelt in front of Zuko and bowed her head. She was crowned with a band of gold spikes that circled her head like a halo.

"Rise, Katara," he said. "Lady Consort of the Fire Nation.
She rose to her feet and planted a kiss on Zuko's mouth. He blushed. This wasn't part of the coronation ceremony. But Zuko's first official act as Fire Lord would be to add it to future ones.
As the dawn broke over Caldera, a crowd of thousands gathered outside the palace and waited for the first appearance of their new rulers.

They cheered as Zuko and Katara descended the steps to the balcony, particularly when they beheld Katara's show-stopping gown.
A tight, low-cut bodice flared out to a wide skirt and a seemingly endless train. What looked like a frivolous extravagance was a strategic statement on Katara's part. Dozens of Fire Nation citizens, the weavers who'd woven the yards of wine-colored silk, the seamstresses who'd put the gown together, and the embroiderers and bead workers who'd adorned the bodice with jewel-colored beads and the skirt with gold filigree dragons and phoenixes, had labored for months to make it.

The hundreds of silver ingots that the gown had cost kept these people and their families clothed, fed, and housed. When the visiting noblewomen and the ladies of the court admired the gown and asked who had made it, the silk weavers, seamstresses, embroiderers, and bead workers would receive more business.
Katara had explained all this to Zuko when he questioned her about the bill.
"And when I'm done wearing it," she had said. "I'll auction it off and distributed the money earned as alms to the poor."
Zuko didn't know if she'd just been making excuses for her profligacy, but seeing her descend the steps, as stunning as a fairytale princess, it was worth every ingot in the royal treasury.
His stomach growled so loudly that it threatened to drown out the speech he was obliged to deliver. He hadn't eaten since sunset the day before and wouldn't be able to until this speech was over. The thought of the fish tempura waiting for him at the coronation banquet was the only thing that got him through the ordeal.

Zuko's close friend, Avatar Aang, was the guest of honor at the combination coronation and wedding banquet. Aang made an exception to his vegetarianism for the fish tempura. Apparently, fish didn't count as meat according to the teachings of the Air Temple monks.
"This is delicious," Aang said. His chapsticks had made short work of the fish tempura and the rice ball and grilled mango arranged to look like a flower it was served on.

Zuko smiled. "Thank you," he said. "I'll make sure the chef gets your compliments." 
Katara blushed.
A few days before, Zuko had joined the fishermen who'd caught the trout-bass used in this dish. He'd done this as a gesture of respect for Katara and Sokka, because it was a Water Tribe tradition that the groom leads a hunting party to catch food for the wedding feast to show that he can provide for his family. For the bride's part, she was supposed to cook what the groom brought back for her. Imagine how surprised the palace kitchen staff was when Katara, their future Fire Lady, came down the day before her coronation demanding to help out.
"I'll have to ask for the recipe." Aang winked and smiled at Katara. She smiled back at him.
Aang had also presented himself as a suitor for Katara but he didn't seem to have any hard feelings. Later that evening, at the coronation ball, he was seen dancing and flirting with Katara's handmaid, Meng.

At the stroke of midnight, everyone left the ballroom and went out into the terrace. Zuko offered Katara his arm. The poor thing was exhausted after dancing every dance. He was pretty worn-out himself. She'd had to take a turn with all the important nobles and ambassadors; him, with their wives.
Katara leaned against Zuko's arm as they watched the fireworks over the harbor. He steadied her by putting and arm around her waist. Her blue eyes were purplish in the blood-red glow of the fireworks.

She stood on the tips of her toes and kissed him.
"Congratulations, husband," Katara said. "Now you've had the honor of kissing a Fire Lady."
"An honor I hope to enjoy many, many more times, wife," Zuko replied.  Fire Lady Katara, my wife. He would never get tired of how that sounded.