Japan's biggest udon noodle restaurant chain, Marugame Seimen, has gained a foothold in Russia, overcoming the obstacles to foreign companies that have kept many of its rivals out of the market.

With Tokyo and Moscow seeking to strengthen private-sector ties, Marugame Seimen's operator, Toridoll Holdings Corp., has shown a way forward for Japanese food service firms in the promising but difficult-to-crack market.

"Fortunately, our business in Russia is robust now," Satoshi Suga, a manager of the international business development division of Toridoll, said in a recent interview.