Can Line live up to its IPO hype?

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Shares of Japanese messaging app, Line, popped up nearly 50 percent on their trading debut in Japan. Now comes the hard bit: Securing a business model that is sustainable in the long run.

Line, which is owned by South Korean internet company Naver, listed on the Tokyo Stock Exchange Friday with an opening price of 4,900 yen per share, 48 percent above its offer price of 3,300 yen, amid heavy buy orders. The stock closed up 31.66 percent at 4,345 yen.

The Tokyo-based company on Thursday made its debut on the New York Stock Exchange, where share prices closed up 26.61 percent at $41.58.

Line's initial public offering (IPO) was the biggest tech IPO of the year, valuing the company at $9.3 billion. Line offered 22 million shares in New York, 13 million shares in Tokyo and an additional 5.2 million shares to meet high demand. Line raised about 132.8 billion yen ($1.25 billion) through the dual listings, in what has been a quiet year for tech IPOs stateside.

Only five listings have taken place year-to-date, as grim economic conditions have kept investors wary.

One of the key concerns experts had was around Line's user base and how the company might grow it in the future. In 2015, Line's global users increased by only 13 million to 218 million total users, after growing by 46 million users in 2014 and by 84 million users in 2013, according to the company's IPO filing with the Securities and Exchanges Commission.

Line's messaging app was launched in 2011 as a mobile platform to be used in place of defective communications after a catastrophic earthquake and tsunami rocked Japan. The idea then grew to become a chat app, focusing on four key markets including Japan, Thailand, Indonesia and Taiwan that account for more than half of Line's total app users.

The company needed to think much more globally in order to build on its user base, said John Roos, founding partner of Geodesic Capital. Roos, who was also a former U.S. ambassador to Japan, said it might be a challenge culturally.

"[Japan] is a risk averse country," Roos said. "Culturally, it doesn't accept failure. It hasn't done as good a job as it could do of celebrating the entrepreneurial successes in Japan."

He added there also needed to be greater mobility of talent, away from the big corporations that offered job protection, to newer ventures, such as Line, that created jobs. While the government had begun to ramp up support for the startup ecosystem, Roos said there was still a long way to go.

Another concern was around Line's revenue; the company currently generates a big share from the sale of emojis and electronic stickers, which experts did not think will find the same kind of traction in the U.S. that the company enjoyed in Japan.

A customer poses next to characters from the Line messaging app as a boy uses a smartphone inside Line Corp.'s LINE Friends Harajuku store on July 11, 2016 in Tokyo, Japan.
Tomohiro Ohsumi | Getty Images

Moreover, competitors including Facebook have been attempting to better integrate emojis and stickers into their messaging products, chipping away at Line's somewhat niche offering.

"The sticker business that Line has, I'm not convinced is going to do gangbusters here [in the U.S.]," said Lewis Ward, a research director at International Data Corporation. "I think there's a very specific culture in Japan and I'm not sure that element will be as strong here."

The company also generates revenue from games and advertising and provides free voice calls and messaging services. Ward added the U.S. market will likely be more receptive to Line's mobile games.

But Renaissance Capital's principal and co-founder Kathleen Smith said the Tokyo-based company holds an advantage over rival messaging apps including the Facebook-owned WhatsApp in monetizing its user base.

"The user engagement is better than any other messaging app," Smith said, adding that Line's focus on boosting bottom-line while operating in a narrow group of countries made it profitable. She acknowledged that in the long-term, Line will eventually have to look beyond Asia in order to sustain their growth.

In its IPO filing, Line said it is expanding beyond providing a messaging service - additional services include mobile games, a music streaming service, payments services, job postings, restaurant reservation service as well as a taxi booking service.

Line is the seventh-most popular messenger app globally, behind WhatsApp, Tencent's WeChat and Microsoft's Skype, according to researcher Statista.

"I think that's what's going to make this very competitive space work well for them, if they're able to execute on a strategy of broadening out and truly selling a platform as opposed to merely the app," added Garvis Toler, global head of capital markets at the New York Stock Exchange Group.

— CNBC's Lauren Thomas contributed to the report.

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