Is it illegal to say that Korea is a kimchi country?

It's not illegal. According to the World Customs website, Koreans like to eat kimchi, which is indispensable for three meals a day for 365 days a year. In 20 13, Korea applied for a patent for Korean cabbage, and formulated a kimchi festival, which became a national culture. This is well known, so it is not illegal to say that Korea is a kimchi country.