For centuries, the Dutch were the only link between Japan and the West. From the 17th century, it was through Dutch traders (the Dutch East India Company) that the Japanese learned about Western technology and culture, just as it was through Dutch contacts that the West gradually discovered more about Japanese society.
Dutch were allowed to live on the small island of Deshima in the bay of Nagasaki. This relation lasted 250 years and ended up in the middle of the 19th century when Japan was forced to open it's borders by the Americans.
External links :
http://www.ndl.go.jp/nichiran/e/index.html