Tu is one of the characters who appears in seasons 3 & 4 of The Legend of Korra. He is the cousin of Mako and Bolin.
Tu grew up in the Lower Ring of Ba Sing Se in the Earth Kingdom and works fruit merchant and the son of Chow and LiLing.
After having spent the night on the streets of the Lower Ring of Ba Sing Se, Bolin and Mako were arguing as to whether they should pull a scam and steal some fruit from a stand. They were overheard by Tu, who challenged them to steal the food while simultaneously attempting to discourage them, leaving the brothers confused. The confusion led to him jumping over the stand and pinning Mako and Bolin to the ground. Shortly after, his father appeared and was able to place Mako and Bolin as Tu's cousins. When his father praised the brothers for their success in Republic City, Tu sarcastically congratulated his cousins and affirmed that he could just be as successful if provided with the same opportunities that his cousins were afforded.
Later, when the brothers asked the family about the new airbenders in Ba Sing Se, Tu told them of a rumor that the Earth Queen was locking them up and experimenting on them, resulting in him being scolded by his grandmother, Yin, for speaking negatively of their ruler.
The next day, Tu managed to get two passports for his cousins to return to the Upper Ring to warn Avatar Korra. Bolin praised him as a good cousin before the whole family shared in a group hug. Sometime later, Tu was listening to a city-wide announcement by Zaheer over the radio with the rest of his family at Yin's house and was shocked to hear of the death of the Earth Queen.
As Ba Sing Se was slowly being consumed by chaos, Tu and the rest of his family tried to convince Yin to leave their family home, though with no success. When Bolin dropped in and announced that there was an airship on the roof to evacuate them to safety, Tu notified his cousin that their grandmother refused to leave. However, after Bolin picked Yin up and carried her out, Tu followed suit. Once on the airship, he thanked his cousins for the rescue, although he added that he could have probably handled it himself if they had not come along.
Upon hearing from Mako that they were looking for the wreckage of the airship that was supposed to take Korra to Ba Sing Se, Tu scoured the Si Wong Desert with a telescope. He found some metal remnants, which prompted them to follow the tracks leading toward the Misty Palms Oasis, where they made a bumpy landing. There, he warned his family in alarm to watch out for an excited Naga, whom he referred to as a "giant dog beast thingy"
Three years after the insurrection of the Red Lotus, Tu was surprised to discover Prince Wu on the Sato estate's doorstep and watched his grandmother faint upon being bestowed a kiss on the hand by the royal.
Later, Tu accompanied his grandmother to the estate's gym, where his cousin had knocked down Prince Wu during their self-defense training. He subsequently listened as Mako relayed part of his past to Wu, though when he told them he had kissed Korra after going on a date with Asami, a surprised Tu interrupted the story, pointing out that he had been under the impression that Mako was dating Asami. Although his cousin ordered him to leave, Tu stayed and noted Mako was in denial by saying that he was not dating Asami when he had kissed Korra. He agreed later on with Wu that Mako's breakup with Asami did not really sound like a breakup and when learning Mako had later gotten back together with Asami, though did not tell that to an amnesic Korra, Tu noted that his cousin was so afraid to disappoint anyone, that he ended up disappointing everyone. He high-fived Prince Wu, who readily agreed with his statement.
Weeks later, Tu, together with Yin, joined the last group of citizens set to evacuate Republic City. They became stranded at Central City Station, however, when Kuvira attacked the metropolis and had her army destroy the train tracks. From atop the station's observation deck, he noticed a platoon of mecha suits heading their way and warned the others. In an effort to find a way out of the city, he followed Wu to Republic City's zoo, where the prince sang to two badgermoles, bringing them under his control. Tu and Wu each climbed one of the animals and rode them back to the station. When the group was later cornered by a trio of Earth Empire mecha suits and Prince Wu readily offered himself as a prisoner in order to save the other evacuees, Tu rushed to the royal's side and implored him not to surrender. He was baffled, however, when Wu suddenly resumed his singing and started to dance with renewed vigor, which commanded the badgermoles to attack the soldiers and crush their machines. Afterward, upon resurfacing and reuniting with the rest of his family, Tu told Mako how level-headed the prince had been during the entire evacuation.