It's been 20 years since the end of the war and the beginning of the era of harmony and restoration. With the help of the avatar and his friends, Zuko had fulfilled his destiny to bring peace and balance to his nation and the world. Apart from some skirmishes in the beginning years after the war, peace reigned supreme and the four nations co operated and lived in harmony. The six war heroes went their own seperate ways to build their own lives.
Avatar Aang, after the end of his relationship with Master Katara decided to restore the way of the Air Nomads. After the end of the war, many people, mostly from the Earth Kingdom, were appealed by the nomadic ways like ahimsa and vegetarianism that they gave up their respective identities to become air acolytes. To make the next generation of airbenders Aang copulated with other air acolytes. The first airbender born in 100 years was named Tenzin. With the birth of other airbenders it looked like soon the air nomads woud soon be restored to their former glory.
Chief Hakoda was still the acting chief of the Southern Water Tribe but most of his responsibilities were taken over by his son Sokka. With the help from the northerners that migrated to South in search of less rigid society norms and technology from the Fire Nation, Sokka worked hard to restore the damage done to the Southern Water Tribe due to repeated Fire Nation raids. WIth the use of technology like the use of airships to trade during winter Southern Water Tribe continued to grow and prosper. Sokka had married his love Suki, the leader of the Kyoshi Warriors four years after the war. They live together happily married with their their two sons, 14 year old Hakoda and 11 year old Arvik.
After the end of the war, Toph had a loss of direction. With a failed reconcilition with her parents, she decided to stick together with Aang and Katara. She left them after sometime claiming to be bored after solving the disputes in the colonies and left for Si Wong Desert to master sandbending and to improve her metalbending. She travelled for a few years visiting the Fire Nation and Omashu. After her legendary duel with King Bumi which she won (age had finally caught upto the Mad King) she refused the offer of being Queen of Omashu. She was also offered to a seat in the council of the Earth King and a position in the military. She rudely declined saying she prefers her freedom to 'sitting on her butt listening old farts'. After a visit to the Jasmine Dragon, she decided to open a metalbending school in Yu Dao at the age of 19. After the creation of the Republic City, a newly formed metalbender squad was tasked to maintain the order and at the age of 22 she became the Captain of the squad. She has two daughters Lin, age 10 and Suyin, age 6, out of wedlock. The identities of their fathers are unknown.
Fire Lord Zuko ascended the Dragon Throne at the age of 16. He reversed the century old policy of warfare and took his nation in the direction of peace. His decision to negotiate peace caused a great uproar in the nation and his early reign was constantly in danger of ending prematurely. Zuko was accused of being a traitor and a coward and selling out to the other nations to keep his throne. Threats from the New Ozai society that still considered Ozai as the Pheonix King, civil unrest due to weak economy and the confrontation with the Earth Kingdom army near Yu Dao nearly destroyed his rule and subsequently world peace. With the help of his uncle and other White Lotus members like Piandao and Master Jeong Jeong Zuko maintained his hold on the throne. Zuko under pressure grew into the Fire Lord the world needed. He reluctantly sentenced Ozai to death for his crimes. This lessened the mistrust of other nations and without Ozai the New Ozai movement soon lost it's steam. He made trade argreements with other to change the war time economy and prevented the economy from crashing. Though the condition was austere due to repairation payments made to other nations, his people didn't lack for basic necessitites like food. His administration spread propaganda publicizing the agni kai between father and son depicting Ozai as a cruel tyrant and him as their saviour, the bringer of peace. The common people were sick of the hundred year war so they wholeheartedly supported the new Fire Lord. Zuko, after the confrontation with the Earth King at Yu Dao began negotiating for the formation of a United Group of Nations. It took ten years after Sozin's comet and eight years after the confrontation for negotiation to complete. It was considered a big victory for the Fire Lord which boosted his prestige both home and abroad.
Four and a half years ater Sozin's comet, Master Katara of the Southern Water Tribe recently ending her relationship with Avatar Aang went to the Fire Nation as the ambassador for both the Water Tribes. There she started working with Zuko and they both resumed their friendship. She helped Zuko in drafting treaties with other nation and they started getting closer due to their mutual understanding of each other. Katara needed someone mature and Zuko was just lonely after his breakup with Mai. Their friendship grew deeper and sooner they started viewing each other as more. Sooner their couldn't control the growing attraction for each other and they confessed their hearts. In the beginning they kept their relationship hidden but when Zuko proposed to Katara and she accepted, they were ready to fight the world to remain together. Their was a great resistance from the nobles but they finally relented after the new agreements that drastically reduced the repairation costs owed to water tribes and significantly improved their relations. Six years after Sozin's comet Fire Lord Zuko, age 22 married Master Katara, age 20. Their marriage was viewed as the product of the new era of harmony and the people of the United Group of Nations especialy Republic City supported them.
Crown Princess Izumi was born in the second year of their marriage. She inherited her gold eyes and raven black hair from her father and the mocha skin from her mother. She had her father's nose and her mother's facial structure. It was previously decided before birth that she would have a Fire Nation name. Katara suggested Ursa but Zuko refused to name her after his missing mother. He didn't want her to be burdened by the weight of her ancestors like he was. She was going to be the future Fire Lord and would inherit a new world. The princess showed the first signs of bending when at the age of 6 she splashed water while feeding turtle ducks with her father. Both their parents were very happy, especially Katara excited to teach her daughter waterbending as Izumi was 'Daddy's girl'. Izumi spent her free time with Uncle Iroh babysitting kids when their parents were busy. She was a good bender, not a prodigy, but her strength was her mind. She was wiser for kids her age and exceeding clever due to spending time with Uncle Iroh. She would make a wise future Fire Lord.
Prince Iroh was born 2 years after the birth of Izumi. He completely resembled his father Zuko with his straight black hair and pale skin and facial structure but he had the round blue eyes of his mother. He looked like as Zuko would look if he had no scar and blue eyes. It was previously decided that it would be Iroh for a boy and for a girl Kya. Iroh turned out to be a prodigy like his name sake showing signs of bending at the small age of three. He also turned out to be a waterbender. Like his father he was gravitated more towards his mother though he equally loved his father. But the most important thing was the bond between the siblings. Izumi was fiercely protective of Iroh and Iroh would always follow his elder sister's lead. Iroh was smart but he acknowledged that his sister was smarter so she took the role of the leader even though he was the better bender. At the age of ten, Izumi had told Iroh that when she would become the Fire Lord he would be her right hand and together they would rule. She told him that she needed him and he promised that he would follow her anywhere. They hugged and it was a defining moment in their relationship.
Princess Ursa and Princess Kya, both twins, were born five years after the birth of Prince Iroh. They both inherited pale skin of their father and curly brown hair of their mother. They were identical twins the only difference between them is the colour of their eyes. Ursa had the gold of her father and Kya had the blue of her other. The news of the twins took the royal couple by surprise and it was finally decided to name them after their mothers. The twins were more close to each other than to their other siblings though they maintained a heathy relationship with Izumi and Iroh. Princess Kya was the one to first bend at the age of 4 and a half. Zuko on learning this muttered about surrounded by goddamn waterbenders which earned him a smack to the back of his head by his wife.
Zuko was living a life of bliss. His nation after a decade of hardship and austerity had progressed greatly in recent years due to boom in technological innovations in the Fire Nation. The common people and the nobility had finaly accepted him as their Fire Lord. The ghost of the warlike Fire Nation had finally disappeared and people have accepted his new path of peace and cooperation. On the personal front, Zuko loved his wife and children. He loved Katara his wife, his lover, his best friend who had helped him to achieve all this and gave him a family that he always wanted. He loved his kids too. Initially he had been scared to death about his parenting skills but with the help of his wife and Izumi he was free of fear after Iroh arrived. He was a happy man and he had achieved inner peace with his family.
It all went wrong when on the twins fifth birthday Princess Ursa bended the wine on the floor.