Originally an ARVN officer (army of South Vietnam), Bao is now the owner and bartender of the Yellow Flag Bar (the name is a reference to the old flag of South Vietnam, which was yellow with three narrow yellow stripes running through it), the favorite watering hole for the Lagoon Company. Bao had founded the bar after he fled the country following the fall of Saigon (now known as Ho Chi Mihn City), just like other ARVN soldiers.

Rock, upon his first visit to the Yellow Flag Bar when he was a hostage of the Lagoon Company, referred to it as the archetypal 'Bar at the end of the world'. The clientele are often the worst of Roanapur's residents – pirates, smugglers, prostitutes and people that had lost all hope for the island. Weapons are usually displayed openly on the bar's tables, possibly an unwritten rule.

Although Bao has retrofitted his bar with a bulletproof-steel plate in front of it (the Yellow Flag Bar is often the scene of many gun battles), it doesn't save the rest of the bar from being shot-up in a gun battle when it happens. And whenever Revy or the Lagoon Company is involved, he demands payment from the Lagoon Company for fixing the bar afterward (which Revy or Dutch never does usually).

(source: Absolute Anime)