Satoru's parents were government officials who served under Fire Lord Ozai and remained loyal to him after he was overthrown, joining the New Ozai Society. Satoru, however, refused to follow suit and ran away. He spent his life on the streets of Ba Sing Se's Lower Ring until his uncle Loban found him and took him in.
Work at the refinery
One day in 102 AG, Satoru was put in charge of the refinery by his uncle, Loban, while he met with his business partner. Satoru met Avatar Aang, his friends, and three members of the Air Acolytes after they had trespassed on factory grounds and Aang had defeated the guards. He warmly welcomed the team, excited to meet them. When he noticed Toph Beifong, Satoru grew even more excited, as he had admired her for a long time, and promptly invited her for a tour of the refinery. He allowed the rest of the team to accompany them as friends of Toph.
During the tour, Satoru explained to Toph how Loban discovered that the land upon which the refinery was built was rich in natural resources, but could not be developed until after the end of the Hundred Year War with the help of an Earth Kingdom business partner. Not noticing Aang's attempts to talk to him about the land's past status, Satoru led the group to a production room where earthbenders, firebenders, and waterbenders worked to mine rocks for jewels, proudly stating that the factory was the future, since people from all around the world came there to work together. To emphasize that point, he showed the team a newer production line where the benders had been replaced by machines, allowing even nonbenders to work in the refinery. Satoru had to cut his guided tour short after Sokka broke one of the refinery's forklifts as it would take the engineer some time to repair it. However, much to his amazement, Toph was able to sense the broken parts and repair them easily through the use of metalbending. After learning that she ran a metalbending school, Satoru asked if she would be willing to visit the refinery from time to time with her students in order to help out with the machines, something to which Toph quickly agreed.
When Aang accused the refinery of being the cause of the nearby river's pollution, Satoru refuted the statement, stating that Loban believed it to be a natural phenomenon. The group did not believe him, though Toph vouched for him, as she could not detect Satoru to be lying. When an argument arose between Toph and Aang, the ground began to rumble violently, causing Satoru to believe that they were responsible for it. After a second quake caused mined crystals to spill out, Satoru urged the team to leave, fearful that his uncle would be angry over what had happened. Before the team could heed his request, they discovered a machine had gone haywire, trapping a worker. Satoru told Toph and Aang to unplug the machine, though they ended up destroying the machine instead. At that moment, Loban returned and blamed Satoru for all the damage to his factory, claiming him to be too "scatterbrained" to shoulder any real responsibility.
Ordered to get the assembly lines back up and running, Satoru was reluctant to admit to his uncle that it would take him some time to repair the damaged machine, so they would have to make do with the older benders' line. Satoru tried his best to get the frightened benders to focus and pick of the pace, as they were on a tight deadline, though was interrupted by Toph, who broke down a nearby wall on her quest to find and talk to her father. Satoru initially just pointed her in the direction of his office, but soon ran after her, having decided to personally guide her there as she would otherwise not have found it. However, he ended up having to defend his earlier attitude toward his uncle to her, as Toph deemed him to be a "sniveling flunky" who groveled for Loban. Angered, he called her out on her attitude, saying that she knew nothing of his situation. Satoru explained that he was respectful and grateful of his uncle because he had been there for him when he needed him the most. He ended their conversation by pointing Toph to Lao's office and left to get back to his work.
When Sokka later came barging into Lao's office, Satoru tried to stop him, but to no avail. He subsequently followed Sokka back down to the iron mine. He came to his uncle's defense when Toph called him out for caring more about money than about people's lives. When the mine caved in, Satoru became trapped underground along with several others.
With Toph growing exhausted from trying to hold the ground above them, Katara gave Satoru her water skin for the earthbender. While giving her the drink, he stayed with Toph at her request, despite his worry that she would lose her concentration. She correctly guessed that Satoru ran away from home, which prompted him to tell her his story of his departure and taking in by Loban. He expressed his initial liking his uncle, believing he really cared about him, but had changed his thoughts, believing Loban to only care about money; Satoru was too scared to be on the streets to see it earlier, thus affirming Toph's opinion that he was a "sniveling flunky". Toph assured him it was not true, but he continued on by saying that he wished he were brave like she was when confronting her father, adding that there was no end to how amazing she was. Lao soon approached the two to talk to his daughter and Satoru stepped aside at his request.
After Aang and Toph's students rescued the group, Satoru watched in concern as Toph collapsed into her father's arms. Not long after, with the spirit General Old Iron making his way to the mortal world, Satoru came back on a forklift, informing Aang that the spirit's mask was being taken by Loban and the Rough Rhinos to the beach. The engineer and Sokka volunteered to retrieve it; en route, the former denied the latter's request to drive the vehicle. Upon arrival, Satoru demanded to know if his uncle had learned the risks greed had put him in, such as the mine collapse from earlier, but Loban merely told him that he did not have what it took to be his successor. When the Rough Rhinos attacked, Sokka gave a confused Satoru his battle club. Running from Kahchi, Satoru asked what he was supposed to do as he had no fighting skills, to which the Water Tribe warrior told him to outthink his opponent. Being chased to the forklift, the young man hit the engine, resulting in the buttons blowing back and knocking out the Rough Rhino. Upon Sokka's return, Satoru asked if the strategy applied to bigger opponents, pointing out to his ally that Old Iron had risen up. With Loban being pulled up toward the spirit because of his gripping the rope he had tied the mask, Satoru and Sokka latched on despite the businessman's protests. They continued to hold on to the rope as Old Iron marched toward the town. When Katara bent up a water slide for them to reach the ground safely, Satoru urged his uncle to let go, telling him to breathe out slowly. The three made their way down the slide and saved themselves. The young industrialist asked Loban if he was all right, to which he was thanked for him being alive.
Within the three months following Aang's defeat of Old Iron, Satoru began his partnership with Toph. One day, during the new Spirits' Friendship Festival, Toph punched Satoru in the arm for not having been back to the refinery in the two weeks since it had opened, to which he expressed his belief that she would just waltz back in whenever she felt like it. He soon watched as the parade marched by his workplace.
Growth of Cranefish Town
When Toph returned with Katara to the Earthen Fire Refinery, which had nearly tripled in size since their last visit, they were enthusiastically greeted by Satoru, who guided them inside to show his fellow executive partner all that had changed. He explained to Katara that they had to hire new guards to protect the factory against an increased amount of break-ins and the increased bender-nonbender tensions in Cranefish Town. He proudly presented his new and improved processing machine that doubled the factory line's ore refining capacity. As Katara noticed the lack of benders at the factory, Satoru's enthusiasm vanished as he explained that his upgrade had been so proficient that it had drastically reduced the need for benders, resulting in the majority of them being fired and the remaining bender employees quitting in protest. As other nonbender owned factories had made the same adjustments to their production lines, more benders had lost their jobs and the tensions between the benders and nonbenders had risen to the point where the former group refused to work for nonbender owned factories. He was thankful for Toph complimenting him on his inventions, noting that she loved them, though was mockingly ordered to never invent a machine that could metalbend.
That night, Satoru was woken up by an explosion at the factory and alerted Team Avatar that Toph had not been in her room.
Satoru and Lao returned the following morning, with the latter informing everyone that similar, seemingly coordinated, attacks had occurred across the city. Satoru attempted to salvage his machine though when Toph later came to check up on him, he sadly reported that the destruction would take him months to repair. As Toph began repairing the damage with her metalbending, Satoru confessed to feeling responsible for bender-nonbender conflict in Cranefish Town. When she pointed out that there simply were not enough jobs in town for skilled benders, regardless of his machines, and that people were just looking for someone to blame, Satoru completed her train of thought by noting that he should probably stop feeling guilty, something Toph agreed with.
The following day, Satoru rushed to Team Avatar and frantically told them that the Business Council building was on fire. As they jumped into action, Satoru informed them that Lao and the other nonbending council members had a meeting and must still be inside. After Team Avatar doused the fire, Satoru ran to the saved council members. When he returned to the factory with Aang, Katara, and Toph that night, a guard informed them that Liling had been freed.
During the final confrontation between Liling's bender supremacists and Team Avatar, Satoru, armed with a metal pipe, and Sokka formed the last line of defense inside the factory. Although Sokka managed to take down one of their assailants, the two of them were shocked to see the remaining benders charge them as opposed to retreating.
After the assault was thwarted, Satoru was present that afternoon when Lao Beifong thanked Suki for her help defending the factory and training his guards to chi block. When she and Aang mentioned the possibility of creating a police force comprised of both benders and nonbenders, he wondered whether or not benders and nonbenders could really work together after everything that had transpired, though Aang and Suki were confident that, with time, they surely could.
- Loban (uncle)
- The Rift trilogy
- Imbalance trilogy
- Satoru (悟る, さとる) means "to comprehend" or "to understand" in Japanese, which ties in with Satoru's profession as an engineer.