WestnEast, a traditional Korean pancake house in the hip shopping area of Garosugil in Seoul, used to be big hit with Japanese tourists when it first opened four years ago, being featured in a famous Japanese travel magazine.
But now the café is feeling the pinch from dwindling Japanese customers.
"Nearly 40 percent of our revenue used to come from Japanese customers, but that's dropped by nearly 70 percent," Lee Kyung-hoon, WestnEast CEO told CNBC.
WestnEast is one of several South Korean retailers reeling from a recent steep decline in Japanese tourists, the largest group of visitors to Asia's fourth largest economy last year, when they accounted for more than a third of all tourists that visited the country.
But a weakening Japanese yen - which has fallen 18 percent against the U.S. dollar since the start of the year thanks to Prime Minster Shinzo Abe's aggressive policies to reignite the economy - has made travelling abroad more expensive for the Japanese. And South Korea is paying the price.
In the first quarter of the year the number of Japanese tourists to South Korea fell by 25 percent quarter on quarter, according to the Korea Tourism Organization.
The yen has fallen over 20 percent against the Korean won since mid-November and hit its weakest level in more than four-and-a-half years at 10.81 on Friday.
(Read More: Woah, Is It Time to Slow That Yen Fall? )
The Chinese Are Coming
But it isn't all bad news for tourism in South Korea because the Chinese have stepped in where the Japanese have backed off. Chinese visitors to South Korea jumped nearly 40 percent year on year in the first quarter of this year, far outpacing the rise in overall visitors to the country by nearly 10 times, according the Korean Tourism Organization.