Matthew Perry ended Japan's Isolation when the US sent him to Japan.
The mountains of Japan and the location of Japan helped lead to some isolation.
No.
isolation
Japan
Japan
after
Ieyasu Tokugawa
When Japan opened some if its ports to foreign trade their long history of isolation ended. So basically, their isolation (or Japanese isolationism) is what ended.
Japan ended its policy of isolation with the Meiji Restoration in 1868, marking a period of increased engagement with the outside world.
In 1868 an American fleet sailed to Japan and forced them to end there isolation.
The United States of America.