At this point, it's quite clear that the Japanese have mastered the American Ivy and prep look. And the brand that started it all was VAN Jacket, founded by a man named Kensuke Ishizu who led a pretty ridiculously awesome life. After a few exciting exploits, Ishizu created VAN in 1951 and soon aimed at conquering the post-war youth market that was virtually untapped as a market.
Ishizu studied GANT, Brooks Brothers, and other classic brands and was soon manufacturing East Coast collegiate styles that, by the mid-60s were cutting-edge style for the Japanese youth. There was even a subculture of Ivy rebels called miyuki-zoku who were dedicated to the look and to VAN. They were quickly labeled "juvenile delinquents" by officials and the media, and were the first of many youth cultures of Japan to flaunt strict social rules with their clothing. But the Ivy look persisted, and Ishizu's influence can be felt in every aspect of Ivy's success in Japan.