Their catchy tunes and sleek moves have helped sell billions of records.

Now, K-pop's biggest stars are helping cosmetics firms sell makeup - to men.

Eager to achieve their pretty-boy looks and smooth complexion, South Korean men are increasingly turning to BB cream foundation and anti-aging products to achieve K-Pop perfection, spending $900 million a year on cosmetics, according to research firm Euromonitor.

South Korea is by far the largest in a growing global market for men's cosmetics, accounting for nearly a quarter of sales in the skin care market.

ABC News

Walk into most any cosmetics store in Seoul, and you're bound to find a men's section selling everything from escargot serum to make-up for men serving their mandatory two-year military service.

The trend is so popular it spawned a nickname for the pretty boys - the grooming tribe. There are even entire TV shows devoted to male makeovers.

"First impression is everything," said JiYun Kim, a spa consultant at Blowblush in Seoul. "They see the perfect skin Korean pop stars have, and they want to look like them."

Blowblush offers a "Men's Fit" course, that includes a salt shampoo to prevent baldness, lifting cream, and a hot stone massage. Unlike facials for women, which largely focus on moisturizing, Kim says male treatments are aimed at soothing skin irritated from shaving daily.

The lucrative cosmetics market prompted Japanese brand SKII to launch its first global men's line in South Korea. The company's best-selling facial treatment essence is priced at $140 a bottle. At SKII's boutique spa in Seoul, male clients regularly shell out anywhere from $225 to $450 for facial and body treatment.

The need to look good has extended to the workplace.

Earlier this year, Korean Air's new staff training session featured makeup and skin care lessons for male staff. Makeup professionals were brought in, so the airline's newest recruits could undergo a three-hour "image making" class, featuring lessons on how best to apply skin care products, sunscreen and BB cream.