It all began in July when Japan imposed export curbs on three high-tech materials to South Korea.
The materials are crucial for the production of semiconductors and displays, two of South Korea's biggest export items.
Tokyo's measures triggered a huge voluntary boycott movement - called 'NO NO Japan' among South Korean citizens.
Those taking part stopped buying Japanese products and refrained from taking trips to Japan.
The latest data released by the Japan National Tourism Organization on Wednesday shows the tourism boycott movement has only become more pronounced.
The number of South Korean visitors to Japan plunged 58 percent on-year in September.
An estimated 200-thousand South Koreans travelled to Japan last month, a sharp tumble compared to some 470-thousand visitors a year ago.
It's also the third biggest drop since Japanese tourism authorities began releasing related data in 2003.
The decline in September follows a seven percent decrease in July and 48 percent drop in August.
Due to the rapid downward trend in recent months, the number of South Korean visitors to Japan during the first nine months of the year recorded some 4.8 million, 13 percent less than the same period last year.
Japanese regions and travel agencies relying on South Korean tourism are especially feeling the heat.
Fukuoka's Beetle ferry service sailing the daily route to Korea's southeastern port city of Busan saw a 70 percent drop in South Korean passengers last month.
Japan's biggest travel agency, JTB, said it had 80 percent fewer South Korean customers in the same month.
The travel agency added reservations for October and November are down by similar percentages.
Kan Hyeong-woo, Arirang News.