- "This won't do you any good! The times have changed! The syndicates can't survive like this any longer. This endless bloodletting is tearing us all apart!"
- ―Mao Yenrai[src]
In the 2060s, Mao was a mentor figure to both Spike Spiegel and Vicious in the syndicate. He also was a good friend of Annie and her husband. When it seemed like Spike had died in a firefight in 2068, Mao was saddened, however, he also "felt" that Spike was still alive, and continued to look for him.
In 2071, the syndicate decided it was time to form a truce with the White Tiger crime syndicate. Mao would be the one to sign it, and Carlos was invited to Mao's chamber on their side. The signing was successful; however, just as Mao expressed aloud that he could "breathe again," he saw Carlos' ship explode and his own men ambushed by Vicious and his team. Facing his death, Mao told Vicious his actions were useless and that times have changed. Lastly, he stated Vicious would never have betrayed him if Spike were present.
Very little is known about Mao Yenrai prior to the events in the anime. He wanted to conduct peaceful business with other syndicates, going as far as to sign a peace treaty with the rival White Tiger crime syndicate. He was apparently very fond of Spike and took on the role of his mentor; it is also implied that he was the one who recruited Spike and Vicious as members to the Red Dragon syndicate. Other little snippets of information about Mao are provided by Annie. It appears that Mao was close to her and her late husband, and she tells Spike that after he faked his death, Mao kept looking for him. He believed Spike was alive because he could "feel" it.
- Mao's name is written in Chinese as "毛恩来", as seen briefly on the treaty between the two crime syndicates. It is likely the fusion of the names of two historically prominent Chinese political leaders, Mao Zedong (毛澤東) and Zhou Enlai (周恩來).