Japanese manicurist Britney Tokyo may not be a household name, but she counts US pop singer Ariana Grande, model Gigi Hadid and TV personality Kim Kardashian among her growing fan base.

The nail artist -- whose designs are finding Internet fame -- was one of the chief attractions at this week's Tokyo Nail Forum, where catwalk models flashed their electric-pink digits and visitors dressed up their fingers in almost every imaginable way.

Glow-in-the-dark nails, glittery blue ones with red flames, nails with yellow smiley faces and unicorns were all on offer. Or how about turning your hands into a recreation of Snow White and the Seven Dwarves?

"People tell me my design is like a fusion of Japan and the US," said the manicurist, who moved to Los Angeles several years ago.

"I say it's Tokyo-meets-Hollywood."

Nail art is taking off in the US and is already popular in China and South Korea. But beauty-conscious Japan is ground-zero for the business.

The domestic market has doubled in a decade to 220 billion yen ($1.98 billion) annually, according to the Japan Nailist Association (JNA), which said there are nearly 25,000 nail salons across the country.

It's been growing since Japan was introduced to US-made artificial nails about four decades ago.

"Japanese manicurists are very detail oriented and always want to improve their skills," said JNA board member Mihori Kinoshita on the sidelines of the three-day nail show.

"That may be linked to the Japanese attention to craftsmanship."

- Aqua-green claws -

But what really super-charged the sector was the introduction of a soft gel that lasts for up to two months, far longer than traditional manicures which start chipping in about a week, said Koji Kawamoto, president of an Osaka-based nail product manufacturer.

"At first there were just a few companies doing this but the market has grown a lot over the years," said the industry veteran.

"The number of manicurists has skyrocketed," he added.

Some 60 exhibitors had booths at the show, advertising nails adorned with stones, ribbons, flowers or ultra-long talons that appeal to visitors like Mizuho Mobu.

The 25-year-old manicurist sported aqua-green claws encrusted with fake diamonds that cost 12,000 yen and took three hours to apply.

Mobu insists her nails are actually shorter than what she's sported in the past. And they aren't holding her back. Not much at least.

"For me, these nails are short. I can use my smartphone without any trouble or do the dishes, but it's impossible to open a can," she conceded.

"The longer the nails, the harder life gets."

Many designs take several hours or more to complete and cost 10,000 yen and up.

Most clients are women although nail art is also popular among some men who like to paint their nails the colour of favourite sports teams on special occasions.

Hand-drawn paintings are also a big hit in Japan. But some people don't have the patience, prompting Britney Tokyo to make some of her designs available in a quick and easy sticker format.

"Painting was also popular in the US as well until last year but now fewer people want to spend such a long time waiting," she said.

"Customers don't want to hang around for two or three hours."