Tsui Choi was a male, Aleena Jedi Master of the Old Republic. While Master Choi may have been diminutive in stature, he was one of the toughest Jedi Masters of his day. Tsui Choi last Padawan was the Anx Jedi Knight, Theen Fida who joined Master Choi on the mission to put down the Yinchorri Uprising, which occurred twenty years before the outbreak of the Clone Wars. Three teams of Jedi traveled to the Yinchorri space in an effort to put an end to the Yinchorri's aggressive actions. Tsui Choi and Theen Fida joined Jedi Masters Eeth Koth and Adi Gallia aboard a Consular-class space cruiser and were assigned to investigate the watery world of Yitheeth.
When the Jedi ships emerged from hyperspace, they were immediately attacked by Yinchorri starfighters. The Jedi ships split up and proceeded to their assigned destinations. On Yitheeth, the Jedi disguised themselves as technology traders, but the ruse was for naught as they were ambushed by a squad of Yinchorri soldiers led by the Devaronian, Olmar Grahrk. The Jedi fought through the ambush however, with Tsui Choi taking out many of the Yinchorri soldiers, which were many times his size. Finding that the Yinchorri command was not located on Yitheeth, Tsui Choi and the Jedi left to rendezvous with the second team of Jedi on Yibikkoror.
They arrived just in time as Yinchorri soldiers had pursued the team to the edge of an atmospheric platform with nowhere left to retreat. The second team of Jedi consisted of Jedi Masters Plo Koon, Micah Giiett, Lilit Twoseas, and her Padawan K'Kruhk. Gathering up the Jedi among the clouds of the gassy planet, the Jedi then traveled to Yinchorr itself to locate the third team of Jedi. En route, the Jedi learned that the Yinchorri discovered where the Jedi were hiding and were moving in to overrun them. The third Jedi strike team consisted of Jedi Masters Mace Windu, Saesee Tiin, Qui-Gon Jinn, and his Padawan Obi-Wan Kenobi.