Happy, let me know if you come across anything of interest. Your perseverance onan expedition for information like this is very impressive. I’m sure you’ll have this problem licked soon.
I tried the same line of research as Happy for a little while with great enthusiasm, but then I suddenly lost interest and had to take a nap.
Ok, I’ll chime in with my miniscule sampling…
I’m of mixed, east-Asian ethnicity and my pubes (the little bit I do have) are definitely not straight, but they have no curl in it. They’re just a bit kinky, like curly hair that’s been relaxed. In all the girl-talk I’ve had with my sisters (5 of them) and my east-Asian girlfriends (about a dozen or so), they have the same straight/kinky hair or sometimes very little or fine hair or sometimes none at all. I’ve also been to the bath houses for women in South Korea (a couple dozen women), and their hair is a tad less straight and thicker–but I still wouldn’t call it curly. This seems to be the same with friends in the northern parts of China (ok, I only knew 1). My friends of south-Asian and middle-Eastern-Asia (only know about 3 that I’ve talked pubes with) have very thick, curly pubes. Filipino girlfriends seem to also have thicker, curlier pubes (2 girlfriends).
Boy, it seems I talk about pubic hair with every single Asian female I’ve known. Dang, maybe I have! The topics of hair, body hair, where to get waxed, plucking vs. shaving, products to use, etc. does come up at least once per person. I worked in a salon in college, so I guess it just got brought up.
My pubic hair used to be curly-ish, but after I shaved it the first time it grew back much straighter. It’s still crinkly and kinky, but it’s not curly. There are, to my knowledge, absolutely no Asians of any type in my family tree.
My pubic hair is quite curly, but my roommate’s is perfectly straight. We’re both black. So uh… I don’t think it’s a race thing. I think it’s more of a heritage thing, seein as my roommate has Indian in his family and all that jazz.
I’ve had the fortune to observe the pubic hair of a certain Chinese gentleman, and it did look decidedly different than the pubic hair of the Caucasians I have observed. Like others have said, kinkyish rather than curly.
It is possible that such photographs on the net have been air brushed to remove the excess hair to make it more appealing to the audience. It is also possible that persons who get photographed in such a manner keep a shaved or trimmed bush.
e.g. The ratio of the number of women with no pubes on porn sites to the number with full grown bushes cerainly does not represent the population of women in general, even within the geographical region of those photographed.
So it’s back to real life research for you… 
You should use this as your sig line.
IIRC during the 50’s Japan had a law prohibiting the exposure of pubic hair. The vid makers and photographers got around the law by having the women hair-free. Even thought the laws re pubic hair has changed it seems to carry over today (haven’t browsed/research to verify). Perhaps that explains some of the hairless pics/vids in circulation? Before anyone 'cite’s me, I googled it and only found references in blogs/other forums etc. And an article on the Manichi Daily News
FWIW I’ve never met straight pubic haired man. 
Not all Caucasians have curly pubes. I know from ahem personal experience. They’re not absolutely straight, but they are kinky or wavy rather than curly. They look quite straight compared to other people I know, especially when dry. No Asian ancestry AFAIK, though I have heard there is some American Indian ancestry on my mother’s side, FWIW.
I keep the area trimmed short because otherwise they tend to just hang there unattractively. If I think it’s unattractive, you can imagine what those porn purveyors think!
chattywine, my husband thinks that my pubes are straight because my underwear smooshes it flat! His pubes, OTOH, are protected–the anatomy holds the fabric off of them, so to speak. That would be his theory as to why you’ve never met a man with straight pubic hair.
This was beautiful, whether intentional or not.
I’m very caucasian and mine isn’t curly, just a bit wavy.
William Congreve, 17th century playwright (Way of the World, Love for Love, etc) wrote a very funny poem on this subject, titled An Impossible Thing.
Too long to quote, but the burden is that a guy makes a pact with the Devil in order to obtain the woman he desires. All Satan wants in return is to be of constant service. Unfortunately, he means this literally. The lover is just about to take a well-earned rest after his first night of passion with the lady, when up pops Old Nick.
It turns out the guy has to think of things for the Devil to do. If he hesitates for an instant, even to hum or haw, his soul is forfeit. Of course the demon performs every task in the blink of an eye, no matter how huge or complex, and is promptly back again for a new command.
Lover desperate, running out of ideas, lady comes to the rescue. Plucking a single pubic hair, “A sprig of the Cytherean grove”, she tells him to ask the Devil to straighten it out. Despite employing all the anvils and hammers in hell, and everything else he can think of, the demon is unable to, disappears with a screech of rage, and all ends happily.
Congreve tells it far better!