Sooni was a poor Korean "working girl" who regularly frequented Rosie's Bar who appears in the Season 7 episode of M*A*S*H titled "Ain't Love Grand". The part of Sooni is played in the episode by Sylvia Chang.
About Sooni[]
At Rosie's, Charles is sulking morosely on his own when he is approached by a pretty, gaudily-dressed Sooni, who brazenly sits down at his table, calls him "Joe" and solicits him to "buy her a burger". Winchester, instantly recognizing her as a prostitute giving a sales pitch, instead gives her a charity dollar and dismissively states he is "not in need" of what she's selling. Sooni, having gotten what she came for, departs indifferently, but suggests Charles reconsider her offer, as "the nights around here are very long; it helps to have some company".
A disinterested Sooni coarsely rebuffs Charles for trying to make her more "cultured" in getting her to listen to classical music and teaching her "table ettiquite".
Winchester ends up falling for Sooni despite her coarse profession and mercenary attitude, partially out of self-deluding loneliness and partially because he finds her genuinely attractive and thinks he can educate and refine her into a woman he can respect, a la Eliza Doolittle in Shaw's Pygmalion. He buys her a nice dress (part of the Klinger Collection), teaches her table manners, and tries to get her interested in classical music. Despite mockery from Hawkeye and Klinger, Winchester indignantly insists (against his better judgment) that she is actually a highborn lady of substance.
Unfortunately, despite Winchester's best efforts, Sooni is (and remains) a simple prostitute, and isn't interested in being "enriched". Happy with a full stomach and a steady supply of clients, she finds Winchester boring and constantly rebuffs his attempts to make her into "some high class broad."