A timeless question unanswered.

I was inspired by Kei's post, "A Timeless Question Answered," exploring fake nails, to ask a timeless question of my own, one which Kei, being experienced in things Japanese, might be able to answer: Why Japanese hair-straightening? It's apparently a technique that comes from Japan--but why would hair straightening be so popular in Japan? Is it actually popular in Japan, or is that just how it's marketed in the States? Is it just that the minority in Japan without naturally straight hair feel especially bad about it, leading to an especially efficient hair-straightening process to fill that niche? Japanese hair straightening seems pretty popular in NYC, perhaps because non-Japanese-American women associate the process with getting Japanese-looking hair. I remain perplexed, and would thus like this timeless question answered.