Miaka was born in Omashu in 130 ASC, the second and last of his siblings, having been preceded five years earlier only by an older brother. By this time, however, his father had taken over as a construction company CEO in the United Republic, making a move from the Earth Kingdom city seem inevitable. Indeed, just four years after Miaka's birth, his family moved to Republic City to join his father.
Miaka was discovered as an earthbender just before the family left the city, and his father was able to use his resources to get him into one of the best earthbending schools in Republic City. It was at this school - General Hishou's Earthbending Academy - that Miaka met future pro-bending rival Sagashi. However, the two really did not speak with each other, although there was no tension between them.
In 143 ASC, Miaka's life was affected when his older brother, Tangek, left the family to join the United Forces. Having been close to Tangek, Miaka worked to make his earthbending stronger and stronger so he could one day join his brother. This led to Miaka developing a "never quit" personality, no matter how tough any earthbending move seemed. His bending advanced throughout his life much stronger than his first thirteen years, however, by 147 ASC, he was still not old enough to join the United Forces, which had an age requirement of eighteen.
Instead, Miaka turned to sport to better his combative skills. Around this time, pro-bending was officially set as an incoming sport. Shortly thereafter, Miaka met firebender Shao Fung in Republic City Park, and the two began discussing pro-bending. The group was soon joined by waterbender Halak, and the three decided to form a team to compete in the incoming sport.
In 149 ASC, the group competed in test matches and successfully won a spot in the league. As one of the best competitors, Miaka and the Winged Lemurs won the right to compete in the league's first ever match. They drew the Aardvark Sloths for the momentous night.
Miaka and his team came out firing. He was quick to defend his teammates, dealing with former fellow student Sagashi for the most part. However, he soon struggled, losing his momentum before regaining it by knocking Sloths' firebender Gatsu back into zone two, but he lost a zone at the hands of waterbender Kuska before getting back at her out of a corner. About ninety seconds in, Miaka fell back to his own zone three, barely holding his ground. However, he held up as his team turned the momentum thanks to a late foul by the Aardvark Sloths. They led late in the round, but Miaka's team lost when Kuska knocked his teammate, Halak, out of the ring with five seconds left, leaving the earthbender and his teammate Shao Fung stunned.
Miaka is a fight-at-all-costs earthbender. His drive is fueled by the desire to emulate his brother and join him in the United Forces someday. This drive has fueled Miaka into a never-quit person, regardless of how much the odds stack up against him. However, Miaka is also friendlier in person, willing to help his teammates both in and out of the ring.
Miaka is a powerful earthbender, nearing a full mastery of the element. He is able to move quickly within the ring and keep opposing benders on their feet, and this also helps him defend his allies when they are in trouble. His bending was so powerful that he was one recruited by a member of the Metalbending Police Force to train in metalbending and join; but he denied the offer to stay with his goal of making the United Forces and also continuing in pro-bending.