CULTURE : Newest Challenge for Japan: Polo Shirts : No leisure means no leisure wear. ‘Casual Friday’ leaves men in sartorial lurch.

In the gleaming lobby of a major trading firm, there is a new and startling sight among the starched white shirts and somber gray suits of Japan’s normally button-down executives: Peach-colored shirts. Green plaid trousers. Sneakers.

Casual Friday has come to Japan, one of the most conservative business climates in the world. In April, Itochu Corp. decreed that employees could dress down once a week, joining the ranks of such firms as cosmetic maker Shiseido, retail giant Daiei Inc., Snow Brand Milk Products Co., textile makers Teijin and Kurabo and IBM Japan.

Like the American firms that originated the trend, Japanese companies say they want to encourage creativity, flexibility--and sales of casual wear. At Itochu, where 40% to 50% of employees don “Friday wear,” the idea originated in the textile division--and was quickly taken up by the apparel division, which held clothing sales in the lobby, employees say.

Hidehito Shima, a 32-year-old chemical division employee in a polo shirt and Reeboks, says casual wear promotes “more frank discussion” in a reticent society. Yuichi Watanabe, 42, said dressing down offers comfort in the sweltering summer heat.

But ask another man why he is outfitted in a suit and tie rather than casual slacks and shirt and he offers a whispered confession: “Because I don’t have any.”

His comment suggests why Casual Friday may not sweep Japan’s corporate world overnight. Yes, the business culture still demands formal wear in meetings with clients.

But the larger issue, people here say, is money.

Casual Friday has unmercifully exposed the glaring hole that many men, especially older ones, have in their wardrobes. They have suits, of course. They have T-shirts and jeans for the weekends. They have golf wear. But under the unwritten rules of Friday wear in Japan, T-shirts are tacky and golf wear is gauche--leaving legions of men in the lurch without casual slacks, shirts, jackets and shoes.

Until recently, casual wear was not needed, fashion experts say, because Japan’s corporate warriors were usually too exhausted for movies or dinners. And because commuting distances are so great, few people have time to run home and change after work; they head straight to discos or parties in their business suits.

For women, who own casual wear because their work lives are not as consuming, the trend has not required such a radical adjustment.

After Itochu began its Casual Friday, the wife of company spokesman Kenji Murakami took a panicked wardrobe inventory and, husband in tow, rushed out to buy him two jackets, two pairs of shoes, one belt, three pairs of trousers and three cotton shirts. Murakami isn’t sure how much it cost--women are in firm control of purse strings in Japan--but figures one outfit might cost $1,000.

Not all wives are so obliging. As strict budget directors, many place casual wear well below other needs, such as housing and education, said fashion commentator Chiyumi Hioki.

And men often lack the confidence to tackle this intimidating new fashion world. Norihiko Fuji of Kinki Nihon Tourist says many men on group tours turn up at the airport in three-piece suits simply because they don’t know what else to wear.

The Japanese can take solace in one fact: Many American men have the same problem.

“That rattling sound you hear is millions of American men shaking, on the verge of a nervous breakdown as they confront the dread of casual Fridays,” GQ magazine wrote.