Japan was completely isolated from the world for 200 years. What they did to foreigners was appalling.
A lot of us are delighted with the Japanese culture and dream about going to Japan someday.
Luckily for us, we are now in the 21st century and we are allowed to go to Japan at any time, contrary to the 17th century when going to Japan was punishable by death!
Sakoku was the foreign relations policy of Japan under which no foreigner could enter nor could any Japanese leave the country on penalty of death.
The policy was enacted by the Tokugawa shogunate under Tokugawa Iemitsu through a number of edicts and policies from 1633–39 and remained in effect until 1853 with the arrival of the Black Ships of Commodore Matthew Perry and the forcible opening of Japan to Western trade.
The policy stated that the only European influence permitted was the Dutch factory at Dejima in Nagasaki. Trade with China was also handled at Nagasaki.