It was for many years one of those guilty pleasures in which teenagers take delight.
In the 1980s, South Korean kids with access to satellite television started tuning in to Japanese channels so that they could rock to the sounds of J-pop. The more daring would record the music and swap tapes with their friends.
By the time they got into their 20s and technology caught up with their growing appetites, they began using the Internet to download Japanese animation and computer games as well.
It is only now that devotees of Japanese pop culture can truly come out of the closet. In the new year, South Korea intends to lift the last of its post-World War II regulations banning the importation of Japanese films, music, cartoons and computer games.
The end of the ban is to be celebrated with a New Year's Eve concert in Seoul by Tube, one of the many Japanese groups that has a following here despite the restrictions.
"Good music is bound to get known. You can't really ban a good product because there are always ways to illegally listen to music," said Kim Kyung Tae, a spokesman in Seoul for Sony Music Entertainment, which is sponsoring the concert.
The ban was a reaction to Japan's brutal colonization of Korea. During the 1910-45 occupation, Koreans were forced to adopt Japanese names and to abandon their own culture and language. In the aftermath, Japanese music was about as welcome in Korea as the operas of Richard Wagner, Adolf Hitler's favorite composer, in Israel.
Today, many South Koreans believe the ban is a relic of the past.
"Just because I like Japanese culture doesn't mean I'm a fan of Japanese imperialism or that I'm less patriotic than other Koreans," said Kang Sun Kyung, a 26-year-old Web designer who lives in Seoul. Kang uses the Internet to watch the films of Japan's premier animator, Hayao Miyazaki, and download music from her favorite singer, Misia. She is even studying Japanese. "I think it's wrong to keep out another culture," she added.
South Korea started lifting the ban in 1998 by legalizing the import of the wildly popular Japanese comic books and allowing art films that had won prizes in international competition. The market was supposed to be completely open in time for the 2002 World Cup soccer tournament, which was held in the two countries.
But the liberalization process stalled as a result of a spat over the contents of Japanese textbooks, which critics here believe trivialized Japan's wartime atrocities. Japanese Prime Minister Junichiro Koizumi's visits to a wartime shrine also slowed the reconciliation process.
Japan and South Korea normalized diplomatic relations in 1965 and are among each other's largest trading partners. In recent years, the reasons for excluding Japanese entertainment products had less to do with history than with protectionism: South Koreans feared that their market would be swamped by the better developed Japanese music and film industries.
"Korean pop culture today is in better shape to compete" with Japan's, said Lee Jin Sik, an official of South Korea's Ministry of Culture and Tourism. "We are more confident about Korean culture. Culture is a two-way street, and this should give a boost to our own industry."
The new law as of Jan. 1 legalizes the import of Japanese pop music, film and games. In addition, restrictions on animation are to be lifted in 2004.
Japanese record companies have been opening offices in Seoul for years in anticipation of the market's opening. Jiro Imamura, a spokesman for the Recording Industry Assn. of Japan, said that at least six companies would be releasing Japanese albums in South Korea in January.
Many of the "new" albums are re-releases. Sony, for example, plans a big promotion for the 1988 album "Endless Rain" by the band X-Japan, which has since broken up.
It is one of many Japanese bands that long has had an underground following in Seoul, especially among college students. The music of Tube, the quartet playing at the New Year's Eve concert, is also well known thanks to a South Korean band named Can, which plays its songs in Korean. (The arrangement exploited a loophole in the complex restrictions on Japanese culture that permitted Japanese pop songs sung in languages other than Japanese.) The bands will play together at the debut concert.
Among many Japanese, the main reaction seems to be: It's about time.
"The reality is that Japanese culture has already penetrated into South Korea to a large extent," said Hiroshi Uyama, a Korea specialist at Osaka International University. "As a member country of the Organization for Economic Cooperation and Development, South Korea must be open not only to Japanese technology but also culture."
Japan has no comparable restrictions on Korean culture, and music and films from the peninsula are increasingly popular among young Japanese.
"One of my favorite actresses is Korean. I watched almost all the Korean films that came to Japan last year," said Hiroyuki Iida, a 20-year-old student in Tokyo, who said he was stunned to learn from a reporter that Japanese products were restricted on the peninsula. "I didn't know that there was still such a barrier between Korea and Japan, but if it's about to get freer, that will be great."
Rie Sasaki of The Times' Tokyo Bureau contributed to this report.