A women goes into the Japan's Suicide forest , when her twin sister disappears in Japan, a young American named Sara ( Natalie dormer ) becomes determined to find out what had happened with her . Sara's investigation leads her to legendary Aokighara forest, located in the base of mount Fhuji . Accompanied by expatriate Aiden, she enters the mysterious wilderness after being warned to "stay on the path." Her investigation plunges her into a dark world where the angry and tormented souls of the dead prey on those who dare to explore the forest.