“Miss Saigon” isn’t typical dinner theater fare. The Vietnam wartime musical is punctuated with PG-13 obscenities, scenes of simulated violence and prostitution and a storyline of (if you have a problem with it, gasp) interracial romance and illegitimate offspring.

That’s the caveat for the Broadway Palm Dinner Theatre’s season-opening production. Ticket buyer, beware.

On the other hand, ticket buyer, rejoice — because this “Saigon” is a surprising winner, another Palm show that takes blockbuster contemporary Broadway material (“Cats,” “Evita”) and, while toning down sheer spectacle, touches on an inner heart.

I doubt the relatively gritty “Saigon” will be a very profitable production for the Palm, though the company deserves a big ovation for its attempt. The show is only lightly censored, with most of the soldiers’ obscenities still intact, handguns discharging here and there and prostitutes sauntering around the stage (“The Movie in My Mind”) to lure GIs.

It says enough that, during pre-show dinner, Palm audiences get an earful of Jefferson Airplane and The Doors — more a Time/Life “Sounds of the ’60s” compilation than dinner theater soundtrack.

For those unfamiliar with “Saigon’s” storyline, it’s about American soldier Chris (played by Patrick O’Herron) and Vietnamese prostitute Kim (played in alternating performances by Akiko Hiroshima and Jihyen Park) in spring 1975; they fall in love amid the horrors of war, though their love is not meant to be.

After Chris is forced to leave, Kim has their love child and spends the following years dreaming of being rescued and taken to America by Chris. But, alas, he has returned to the States to marry a girl back home (Cheri, played by April Monte). When he gets word of his child, he must decide between a love that once was and a love that now is.

In the periphery, the Engineer — a Vietnamese pimp, played by a Fericito-
looking Seth Wyatt Kinney — schemes to use Chris’ and Kim’s child to get a green card for himself. As in most regional productions of “Saigon” with a charismatic Engineer, he ends up as the show’s charmer.

Most of the Palm’s cast was hired out of New York and is a blend of Asian and faux-Asian imitators. (Finding actors to play Vietnamese men, director M. Seth Reines tells me, was especially hard.) Consequently, some of the Vietnamese characters are played by Hispanic and Caucasian actors. It’s acceptable enough, though concessions in casting result in an ensemble vocal tone that’s slightly less smooth than the Palm standard.

Hiroshima, who tackled the lead on opening night, has a gorgeous, almost Japanese-pop voice — and her duets with O’Herron (“Sun and Moon,” “The Last Night of the World”) are sweet confections. It’s her performance in the heartrending second act that solidifies this show and makes it transcend the realm of dinner theater.

If there’s a misstep in the show, it’s a minor one: Monte, a Valley actress I adore, never quite gets a grasp on how Cheri should react to her husband’s relationship with Kim, and the women’s second-act confrontation (“Room 317”) feels awkward as a result.

“Miss Saigon” ends on a harsh note and much of the opening night audience was left visibly stunned as they walked out to their cars. I liked it. Dinner theater could use a jolt now and then.