Lifenet Insurance Co. debuted Thursday on the Mothers startup market at the Tokyo Stock Exchange, becoming the nation's first listed life insurer that operates only online.

Its initial share closing price, however, was a tad off the IPO price.

Taking advantage of its low-cost structure with fewer sales staff, Lifenet, which started business in 2008, has been popular with young people and has grown rapidly. About 75 percent of its new customers in fiscal 2010 were in their 20s and 30s, and the insurer had 113,095 policyholders as of the end of February.

Its life policy premiums are about half that of its major rival firms, according to Lifenet Insurance.

"We'd like to gain the market's trust by succeeding in this early debut," Lifenet President Haruaki Deguchi told reporters Thursday.

The insurer, however, ended the first trading day at ¥995, after kicking off at ¥930, against its IPO price of ¥1,000.

In the short term, Lifenet expects to post a ¥1.15 billion net loss for the business year that ends March 31, against an ¥834 million net loss the previous year, mainly because of the costs of going public.