When Bolin asked how Korra and Asami's vacation had been, Mako noticed how the women turned to each other, conversing in hushed tones, and called them out on their strange behavior.

As such, he was the first to respond to a call about Mako and the others soon decided that they would not leave Ba Sing Se before having freed the airbenders, even though the Queen had ordered them to leave. Mako later got a phone call from a distressed Korra, who told him she had reason to believe Asami Sato had been kidnapped. In the following months, Mako joined the Republic City Police Force, where he steadily rose up from being a beat cop to a detective. Being helped to his feet, Mako comforted a downcast Bolin, who admitted to having been given the slip by Tokuga, by formally acknowledging their partnership. Toza came to help out the two and Zolt called off the beat-down, claiming the brothers were more trouble than the were worth. Lighting is very potent but the ease to which it can harm those around one has lead Mako to avoid using it unless he is in a situation where possible causalities would be acceptable if he missed his mark. He reminded her that the Triple Threat leader was unhinged and that she should not let him manipulate her as such. As they left Lin's office, Bolin remarked to Mako that he guessed that the lead on Wonyong had been a dead end, but Mako remarked that he did not think so, and that the two should pay a visit to Two-Toed Ping. Korra told Mako that she believed it was the Creeping Crystal Triad who were responsible for the kidnapping, and asked if Mako knew where they were located. The police force had their hands full investigating the triads ravaging the city, as the different factions engaged each other in turf wars over the land that was not destroyed during the invasion.

Jargala told the group to search for any trace of Asami Sato, because she did not have the businesswoman at the hideout. Lin sternly responded that they would not be, because Wonyong was powerful and well connected, making him difficult to get to.
Republic City was founded on a destroyed piece of land that needed to be tended to, as a result it became an invitation for members of all other nations to join together to form the society. Mako encouraged his brother to metalbend them out of there, though Bolin failed. He tends to act in a critical and controlling manner, stemming from a life on the streets and a drive to protect his little brother, which forced him to take on adult responsibilities at a young age. What about Inez? Inside were some bodyguards, who were only just regaining consciousness. With Tenzin's help, the threesome managed to navigate their way to lower parts of the building, though their escape routes were soon blocked by the advancing lava. During the ride back, Bolin engaged in small talk with Two Toed Ping, much to Mako's annoyance, who gruffly corrected his brother by placing emphasis on the temporary nature of their partnership. Mako was born the son of an Earth Kingdom man named San and Naoki, a Fire Nation woman, two years before Bolin. Mako responded that he doubted that, and questioned where Skoochy's clothes had come from, to which Skoochy replied that he had "found them". Mako ignored Bolin, saying that they had need to find Tokuga and to radio Beifong for backup. Mako and his friends fought back for a while, but the sheer number and power of the Equalists forced them on the run. The Legend of Korra was initially conceived as a twelve-episode miniseries.Nickelodeon declined the creators' pitch for an Avatar: The Last Airbender follow-up animated movie based on what then became the three-part comics The Promise, The Search and The Rift, choosing instead to expand Korra to 26 episodes. So like, most citizens of Republic City, Mako is of mixed nationality, his father, San, was from the Earth Nation and his mother, Naoki,  born in the Fire Nation. He also appears to be an adequate cook, preparing meals for himself and Bolin. Mako added to Lin that he believed that the Triple Threats had been bought, and that Korra had a hunch it was Wonyong Keum. Mako ordered the military's Mako and Bolin rushed to Guan and Sheng's aid after Kuvira tried to use the brainwashing device against them after feigning her willing surrender. Mako told the young triad member that he had heard that he might know where the Triple Threats' hideout was, but Skoochy responded that he would not know because these days he was "living on the straight and narrow". The brainwashed brothers demanded that Kuvira release them. He said he thought it was possible, and suggested that they bring Wonyong in for questioning. He and Bolin made to escort Kuvira back to the airship, where she was locked up and would be brought to Zaofu before the election.Once aboard the airship, the party was ambushed by Guan and his army. Bolin responded that maybe they should be, and proposed some titles, including "Good Cop, Bad Cop," and Mako said that he was assuming he was the bad cop in the scenario. They were successful, though the team was broken up when an angered In the aftermath of finding Korra, Amon launched his grand attack on the city.

After forgiving his brother for their past argument, he explored the Inside, Mako and Bolin headed to the power core of the machine, where they took to battle with the present guards. As the two walked away from Ping's cell, Mako remarked that Bolin had displayed some good thinking, and would make a fine cop one day, to which Bolin responded that he had learned from the best.