After World War II, Japanese popular culture was "banned" in Korea. However, despite the official ban, Japanese popular culture was introduced and circulated through hidden or unofficial channels. In fact, the author, born in Seoul in 1976, grew up watching the animated TV series Astro Boy with its theme song in Korean. He recalls that it was not until the 1990s that he learned that Astro Boy was produced in Japan. Why was Japanese popular culture banned? How did Japanese popular culture spread in Korea despite the ban and the changing political situation? This book analyzes the history of how Japanese culture has been accepted into Korean society, citing numerous animated and visual works as examples. Japan-Korea relations have undergone dramatic changes, and although Japan and Korea are increasingly linked in terms of politics, economics, and cultural production, the relationship remains fragile due to the colonial history of the two countries. This book is a unique attempt to rethink postwar Japan-Korea relations from the perspective of transnational cultural space.