Honor is of high priority in the Fire Nation
Unless he tries to blend in, Kazuto is someone that tends to leave a strong impression to anyone that he approaches. When interacting with someone, he wants their full attention. He's a man of manners and chivalry. If he's in a good mood, he'll give respect to his fellow man by default, but doesn't take to kindly when other people are rude to him. He can be very blunt with the exception of confronting women, in which he tries to be as nice as possible. He'll even show some tolerance to a woman if they give him an attitude.
His biggest passion is firebending and will do anything he can to incorporate his abilities in everyday life or competition. He's not a stranger to commitment and hard work, since it's those qualities that got him to his level of skill. And when he decides on big goals, he'll be extremely determined to reach it no matter how improbable it may seem. Because of his skills he tends to underestimate others and won't stop himself from instigating potential opponents.
Kazuto's biggest irrational fear is of stinging bugs, anything from scorpion-bees to vulture-wasps. He had a very bad experience as a small child. He never had any training with blades and is very uncomfortable when confronted with sharp objects.
Kazuto is very proud of his heritage and his family. Because of this, committing the crime of firebending the day of Sozin's comet's arrival is his biggest regret. Ever since he committed his crime a year ago, he has actually become much more mature than he normally was (see history for details).
At the start of his journey from the Fire Nation to the Earth Kingdom continent (see history for details) he wore his Fire Nation uniform. But because he wasn't putting effort to maintain the uniform and because he learned not to give himself as much attention, he eventually abandoned his uniform for clothes typical of rural Earth Kingdom citizens. He currently carries a sleeping bag and light camping gear, traveling the Earth Kingdom by foot. Surprisingly obtaining money has not been an issue as he's managed to earn it through firebending duels and performances. He actually plans to eventually travel to Republic City to attend the "Pro-bending tournaments" in effort to obtain money (and show off his skills). AT ALL TIMES, Kazuto wears a headband, even while sleeping.
Kazuto was born of a noble family in the Fire Nation Capital. His family comes from a long line of Imperial Firebenders that have serve in the Fire Lord's palace for generations; both his father and mother serve as Imperial Firebenders and his brother (3 years older than him) became one by the time Kazuto was 15. Already at that age, Kazuto obtained an exceptional skill for firebending. His greatest teachers were his own family members. Kazuto was extremely proud of his family and was always willing to fight (non-lethal) Agni Kai duels against other nobles his age. He had even fought against the Fire Lord's own children (though lost most the those duels).
Kazuto was 22 when Sozin's Comet had arrived and passed through the Earth's Atmosphere as it does every 100 years. The Fire Lord had ordered a prohibition of firebending on that day as an act of reparation to the other nations for the violence that the Fire Nation had committed the last 200 years. Any firebender of the Fire Nation caught firebending would be severely punished. While this prohibition was announced months before the actual date, many young firebenders had secretly perform Agni Kais. Many were filled with the temptation to demonstrate their powers with the comet's energy. Others, like Kazuto, decided to participate in Agni Kais out of peer pressure, as rumors would go around to make fun of family's too "weak" and "scared" to fight in the name of their family's honor. It was to the point that some were convinced that the Fire Lord was going to look a blind eye to any reports of firebending on the day of the comet's arrival. Those who believed so were terribly mistaken.
The Fire Lord had ordered soldiers to patrol every single island of the Fire Nation, even those uninhabited. And sure enough, many firebending duels on that day were discovered and offenders were arrested on site. Kazuto himself was caught red handed (literally) when soldiers (authorized firebenders) interrupted his duel and arrested him. All those that were charged were taken to the Fire Nation Capital where over a hundred criminals, after being tortured in jail cells, were gathered and displayed to the public. Officers gave speeches, displaying that the Fire Lord was not joking about enforcing harsh punishment to offenders. As a final punishment, each offender had their name called aloud for people to hear. As the were called out individually, they were branded in public. The hot brand was the inscription of the calligraphy of the word, "shame." The names were then to be displayed in a small public shrine near the center of the capital - a "hall of shame."
After Kazuto was finally released he made the painful decision to confront his family. His father was standing at the front door of their household. At the sight of Kazuto, his father screamed at him at ordered him leave the vicinity of their home immediately. Kazuto leaving without resisting he never got to see his mother or brother. In public, people would boo at him and throw objects at him. Many stores and taverns would not welcome him. Tormented for the mistake that he left the capital and fended for himself in the wild for a small period. He tried to think of anything that he could do to regain his honor.
He finally came up with a plan. Kazuto would accomplish something that no Fire Nation citizen has in over 100 years. Kazuto had decided that he would search for a lost population of dragons in which he could present to the Fire Nation. 200 years prior, dragons were highly respected by the Fire Nation as they were the ones who passed the firebending art to humans. But ever since the war 200 years ago, dragons were hunted to extinction. Nonetheless Kazuto had hope. Noting the fact that Avatar Aang had managed to discover a population of Sky Bison, once thought to be extinct, Kazuto thought that there had to be dragons out there, still hiding. Kazuto is now exploring the Earth Kingdom to find leads and information to achieve his goal.
***Note: Kazuto has no clue that there are at least two dragons likely still in existence, guarded by the Sun Warriors, which are unknown to almost all of society.