With the world's 10th-largest population, Japan would appear to be a fruitful place for retailers to find ready and able consumers. However, with a shrinking middle class and a slow-growing economy, competition between businesses has increased, leaving some retailers outside the corporate loop. As The Wall Street Journal reported today, Wendy's/Arby's Group (NYSE:WEN), run in Japan by Zensho Co., has decided to leave the country after almost 30 years in operation.

Says the Journal:

With 60 regular employees and 1,900 part-time workers, Wendy's Japan racked up sales of 6.2 billion yen in the fiscal year ended March. Despite posting a profit in the previous fiscal year, Zensho has decided to focus its resources on other businesses such as its Sukiya beef bowl chain.

This seems like good news for rival international food chains such as Yum! Brands (NYSE:YUM) and McDonald's (NYSE:MCD), the latter of which is already performing quite well in Japan. In addition, Burger King (NYSE:BKC) seems to be on shaky ground; it left the country in early 2001 but returned in 2007.

What do Fools think -- is Japan ripe for more American-style fast food, or will it favor a greater focus on regional cuisine? Would you invest in a Japanese retailer considering the country's economic problems and aging population? If you've got an opinion on any of these stocks, or Japan in general, drop a comment in the box below, or come join us on CAPS, absolutely free, to learn more about these and countless other interesting stock ideas.