|Alias||The Blue Spirit|
|Occupation|| Slave (formerly)|
Hiro lived in a small Fire Nation village. As a child, he showed a natural talent for firebending and was fond of stories of the Blue Spirit. However, one day, slavers arrived, killing all the adults, including his parents and enslaving all the children. Hiro was eventually sold to a bandit leader named Goro, along with Rai and Kala. Because of his firebending skills, he was assigned to work in the forge, during which time he was regularly abused by his masters every time he made a mistake or didn't accomplish a task fast enough.
One day, Hiro was gathered outside with all the other slaves and forced to witness the brutal beating to death of Kala, who had disobeyed her master by supplying Rai with food and water while she was being punished. Suddenly, Rai ripped out of her restraints with incredible force and began bending all the elements, revealing herself as the Avatar. In the chaos, the bandits fled, leaving their slaves behind.
Hiro and the other slaves were found by authorities while Rai disappeared and he was returned to some extended family. However, due to the trauma he experienced, he was unable to go back to having a normal life. So, he packed up his things and left to journey on his own to help others, taking on the guise of the Blue Spirit and becoming a vigilante while also trying to find Rai.
When he finally found her many years later, he joined her traveling party, though she was indifferent to him. He pledged his loyalty to her, but she quickly scolded him, claiming that he was acting like a slave simply trying to fill the void of a lost master. Despite this, Hiro is very loyal and devoted to Rai and harbors strong romantic feelings for her.
After joining her group, Hiro was quickly at odds with Takumi and Sati, especially when the pair tried to convince Rai to do something. Hiro, believing himself the only one capable of truly understanding Rai, often argued with them and declared that Rai didn't have to do anything they said. Despite his great dislike for Takumi, Hiro still came to his rescue, proclaiming that even if he did not like Takumi, as the Blue Spirit, it was his job to help those in need.
After Rai was supposedly killed by the slaver Ryota, while Takumi refused to believe she was dead and Sati unsure of what to do, Hiro channeled his grief into vengeance, determined to hunt down Ryota and avenge Rai. Realizing the destructive path this would take him down, Takumi and Sati joined to look after him. However, they were captured by Ryota, who revealed himself as Rai's brother. When Hiro's identity as the Blue Spirit was discovered, Ryota chose to auction off the chance for other slavers to beat him as payback for his vigilante actions. Rai returned in time to save her friends, but Ryota escaped.
They pursued him all the way to Ba Sing Se, raiding several slaver cells for information. After Ryota fell to his death in an unintended suicide, Hiro insisted that they give Rai the time she needed to mourn her brother. When he, Sati and Takumi later went out to a restaurant, they were joined by Goro, whom Hiro immediately recognized and tried to attack, but was prevented by Goro. After Rai unleashed her Avatar powers on Goro, Hiro stopped an individual from photographing the event, though this did little to stop the spread of news of the Avatar's return.
Hiro joined Rai alongside Sati in their final confrontation against Goro, but Hiro was ultimately subdued when Goro used his bloodbending to twist Hiro's arm until it broke, thus incapacitating him. In the aftermath of Goro's death, Hiro tended to Sati while Takumi tended to Rai.