Yao is one of three aspiring warriors who joined the Imperial army, the other two being Chien Po and Ling. He is the shortest, both in stature and temper, among the three.
When Sora, Donald, Goofy, and Mulan attempt to join the army, Sora is attempting to get in line when Yao cuts in front of him. When Sora objects, Yao punches him in the face, which leads to a massive brawl between himself, Sora, Donald, Ling, and Chien Po, which Goofy attempts to break up and Mulan succeeds in breaking up. While he disliked Sora and co. at first, he softened his attitude towards them after they saved China from Shan-Yu and the Heartless.
One of the men drafted to help defend China from the Hun invasion.
Yao’s a compact sort of fellow who likes to brag that he’s tougher than anybody else.
Yao Ming Interview on Shanghai Disney
Animation – How to draw Yao from Mulan
Mulan – Yao made a friend
Mulan – Yao, Ling and Chien Po