She is the sister from Lee and a Member of the White Tigers. Her Bit Beast has the Name Galux. Mariah has feelings for Ray, the Ex-Member of the White Tigers. Mao was born in a secluded mountain village community in China, and was the younger sister of Chou Lee. Because their home was isolated from society in general, it did not possess modern technologies such as computers or cell phones. As such, Mao spent her time with her friends Gao, Kiki and her brother's best friend Kon Ray. Mao was especially close to the latter, as Ray was the one to give her first beyblade, and helped her practice, leading Mao to be fond of him. The group often practiced Beyblading constantly, alongside doing chores around the town.
Eventually, the group came together as the Chuugoku, planning to one day become the greatest beybladers on Earth. Mao is completely loyal to the team, and always tries to keep the peace within it, her cheerful attitude and support of her teammates making her a valuable addition to the Chuugoku; with Mao also serving as second-in-command. Her bitbeast is Galux; passed down from her ancestors in the Minx Tribe. In battle, Mao often liked to taunt other bladers who think she can't beat them and because of her speed, tending to knock opposing bladers off their guard. Mao eventually came to believe that a win in beybattling does not truly count if you don't have fun during the battle.
Mao became very loyal to Ray, and the two eventually became friends. She became angry when Ray, upon receiving the power of Byakko as a sign of him becoming leader of the team, apparently deserted his friends and left the village. Nevertheless, Mao remained loyal, due to her friendship him, and was the only team member who didn't want revenge on Ray, but was forced to by Lee (who most especially wanted vengeance).
Mao and her team went to the Asian Championships in preparation to go to the World Championships in Russia, and it was here the Chuugoku faced off against Ray and his new team; the BBA Team. In the finals, Mao was (barely) defeated by Ray after a vicious battle, when Mao's beyblade stopped spinning mere seconds before Ray's at the end of the match. It was during the battle that Galux and Drigger stopped fighting each other willingly and surrounded the stadium in emotional energy, making Ray and Mao remember the good times they had together. Upon Blader DJ's announcement of her loss; Mao had hard feelings towards Ray, as she missed being his friend, and the two began considering to hang out for some time.
The rest of the team, upon loosing the championship, would later come to repair fences with Ray, especially Lee. After the BBA Team won the World Championships and eventually disbanded, Ray eventually returned to the village and led the team; named "Baihuzu" in G-Revolution series.
In the manga, many years later, Mao consummated her relationship with Ray by marrying and Mao gave birth to his daughter; Rin.