TOKYO, Japan — Fast Retailing, the parent company of Uniqlo, Theory, and J Brand, will offer a four-day workweek to about a fifth of its workforce starting in October, the company confirmed to Bloomberg. About 10,000 full-time employees at Uniqlo's Japan locations will have the option of a three-day weekend in exchange for 10-hour work days the rest of the week. The retailer is also considering introducing a shorter week at its corporate headquarters and at more stores, if this trial goes well.

The perpetual three-day weekend is a fantasy often associated with white-collar workers, who can afford to cut hours. Yet Fast Retailing is offering the perk to its in-store employees with the hope of retaining full-time talent, who often cut down to part time to be with their families or care for elderly parents, the company says. The one downside of the setup is that workers will have to work Saturday and Sundays to help Uniqlo keep its stores staffed during its busiest times.

The move comes at a time when a few of Japan's corporations are just beginning to rethink the traditionally arduous workday. About 22 percent of Japanese workers put in more than 49 hours a week, compared with 16 percent of U.S. workers, according to data reported in The Guardian. As a reaction to overwork and stress from traditionally long hours, some Japanese companies, including trading house Itochu, have banned late nights.

Many have made the case for more flexibility in hours for workers across industries, but it's unlikely that the four-day workweek will become commonplace soon. While the four-day workweek is on the rise in the U.S., the most visible success stories are at small companies with highly skilled labor. In a 2014 survey of more than 1,000 employers, 43 percent of companies said they allow at least some employees to compress the workweek, logging longer hours on fewer days, for at least part of the year, up from 38 percent in 2009. Only 10 percent, however, of those employers, usually small companies, offer the perk to all their workers, the survey found. A major challenge to the four-day workweek is that the majority of the world operates on a five-day schedule.

Treehouse, a Portland (Ore.) online education company with fewer than 100 employees, has committed to a 32-hour workweek so that employees have more time to spend with their families and loved ones. The chief executive, Ryan Carson, has said that employee retention is "amazing."  Some argue the shorter weeks also help with morale and productivity.

Retention is particularly important to Uniqlo, even for its lowest-skilled workers. Uniqlo puts its new retail employees through a two-week training, and losing that talent costs the company money. "We feel we have to enrich them," Uniqlo USA Chief Executive Larry Meyer told Bloomberg in March. "If people are happy, the retention rate is high. If not, the retention rate is low."

Uniqlo has come under fire in the past for worker conditions at its suppliers’ factories in China. Following internal investigations, the retailer has promised to take action to ensure“appropriate working conditions” for the people who make its clothing. A 2011 book, The Glory and Disgrace of Uniqlo, by journalist Masuo Yokota claimed that some store managers in Japan were overworked. Uniqlo sued the book’s publisher, but the case was dismissed. The company said at the time that it was working to “adopt a strict stance” against unpaid overtime.

By Rebecca Greenfield, Kim Bhasin; editor: Alex Dickinson.