TOKYO, May 14 (Reuters) - Ask Yukihiro Katsuta what anyone could possibly need for sartorial comfort beyond heat-generating innerwear in winter and a breezy, cooling undershirt in summer and he'll tell you that Uniqlo, the Japanese casual-wear brand, is just getting started.
"I want about 15 'brands' like that," the head of research and design at Uniqlo said, referring to the hot-selling Heattech thermal line and the silky, feather-weight Airism series, the latter of which earned the status last year as a strategic stand-alone brand within the Uniqlo universe.
The next Heattech would be welcome right about now.
Uniqlo's parent, Fast Retailing Co, has made its name as a maker of high-tech, functional and affordable clothing, beginning with 1,900 yen ($18.60) fleece jackets in the late 1990s, helping founder and CEO Tadashi Yanai become one of Japan's richest men.
Fast Retailing has enjoyed years of record sales thanks largely to rapid expansion overseas, but its profit margins have fallen for three consecutive years in Japan due to a rise in discounts and higher labour costs.
Some analysts are also concerned the company's "wow" factor has been missing of late. Ultra Light Down, which along with Fleece, Heattech, and Airism is among Uniqlo's technology-backed brands, is a decade old, and the addition of modified products such as a line of extra-warm Heattech wear has largely going unnoticed.
Airism, for its part, succeeds the Silky Dry and Sarafine lines that offered a similar, though somewhat inferior, feature of a soft, cool and dry touch.
"Airism is great, but it's essentially a new name for something they already had," said Masafumi Shoda, head of Asia-Pacific consumer research at Nomura Securities. "There's a sense of stagnation when it comes to new technology at Uniqlo."
Katsuta is impatient to change that. The drive for innovation has especially heated up after Uniqlo last year launched a new strategic direction under the "LifeWear" concept, which aims to create "the next category of clothing" that brings comfort and functionality to a new level.
"If we could have 10 tomorrow, I'd want 10," he said. "When people think of Uniqlo in the winter, they think of Heattech. We want our stores to be an amalgamation of those kinds of products."
One idea? "Mr Yanai talks about the size conundrum," Katsuta said. "What if you could order something online and have it fit perfectly? You wouldn't have to go shopping after work. (LifeWear) is all about what we can do with clothes to adapt to people's changing lifestyles."
A large part of succeeding with Airism undershirts and camisoles, Katsuta says, is getting the message out.
"We have to communicate to people what happens when they wear it," he said. "It was the same with Heattech. At first the reaction, especially in the United States, was, 'What the heck is this?' But one day (in 2008), we handed out thousands of free samples in Times Square, explaining the made-in-Japan technology. Then, people were sold."
By 2013, Uniqlo had rung up 300 million Heattech items worldwide. Fast Retailing expects demand for Airism to eventually outnumber that as it promotes the concept of "putting on rather than taking off innerwear as a relief from heat and humidity".
In between the big-brand launches, Uniqlo is playing up incremental technological improvements, born of clues from the sales frontlines and elsewhere, to help propel sales.
New this spring/summer season is the Dry Stretch Pants line - a concept that originated from golfer and Uniqlo brand ambassador Adam Scott, who was looking for thinner trousers with more range of motion.
"It's been a while since I've been this happy with a new item," said Katsuta, wearing a pair of khaki Dry Stretch Pants with a red-and-white-checkered button-down and grey-blue cotton cashmere sweater, also from Uniqlo.
"(Scott) played at the Masters in these very pants several weeks ago," he said. "But it's LifeWear. You can wear it 24-7, 365 days. With these and a (Uniqlo) polo shirt, you can dress for the office for less than 5,000 yen ($49)."
Among updates for this year's fall/winter collection, previewed in Tokyo on Wednesday, is a line of men's Ultra Light Down hooded jackets that has an aluminium-coated lining to keep the wearer warmer.
Also new is high-tech fleece material, developed with Japanese textiles maker Toray Industries, that is about 1.5 degrees Celsius warmer than previous products.
$1 = 102.2250 Japanese yen Additional reporting by Ritsuko Shimizu; Editing by Matt Driskill