Inside one of the fastest growing private companies

In a world where start-ups are gaining notoriety by quickly capitalizing on the idea of new innovation and technology, entrepreneur Vicky Tsai has built a multimillion dollar brand doing the exact opposite.

Tsai is founder of San Francisco-based Tatcha, a luxury skin-care line based not on new trends, but on centuries-old geisha culture and tradition from Japan. She was ranked No. 21 on Inc. magazine's Inc. 5000 List for 2015. The list features the fastest-growing private companies in America.

While interning at big beauty companies during her time at Harvard Business School in 2005, Tsai developed acute dermatitis as she tested various products. She took oral and topical antibiotics and steroids that got her skin under control, but doctors said her skin was permanently sensitized.

After graduating in 2006, she worked for Starbucks in China when a layover landed her in Japan. There she picked up a product she wasn't able to find in the U.S.: a blotting paper used to absorb oil off the skin. Turns out geishas are also big fans of blotting papers. Tsai eventually was introduced to a geisha, who took her to an apothecary to help Tsai select products she uses to care for her skin. Within a few weeks "my skin went back to normal," Tsai said.

She went on to research materials used in Japanese skin care and decided to launch her own beauty line. She sold her car, engagement ring and worked four jobs to finance her business, formally launched in 2009.

Tsai also hired a full-time researcher and translator, who discovered a book of Japanese beauty rituals written down in 1813, on which her beauty line draws. "It took us a long time to procure the book, but thankfully we did," she said. "We started bringing the formulas and approach of skin care back to life. You would think it would be complicated or exotic, but the approach was so simple."

Today, her animal-safe beauty line is sold online globally, and in big U.S. retailers including Sephora and Barney's, as well as Joyce Beauty in Hong Kong. Her first product? Blotting papers.

Her luxury brand has since expanded to include a full line of products, including a travel-size hand cream for $8 and a four-piece skin-care regimen for $395. She's cracked the prestige U.S. beauty industry that reached $11.2 billion in 2014, according to a report from researcher NPD Group. The prestige beauty category includes products sold mainly in U.S. department stores.

Inc.'s report pegs Tatcha's growth rate at nearly 11,000 percent from 2011 through 2014, and her 2014 revenue at $12 million.

Much like the book Tatcha is based on, she hopes her brand has staying power. "The ultimate dream is to have a brand that is around for the long haul," she said. "A brand that in 100 years outlives me."