From VICE:
The Aokigahara Forest is the most popular site for suicides in Japan. After the novel Kuroi Jukai [The Black Forest, written by Seichō Matsumoto in 1960] was published, in which a young lover commits suicide in the forest, people started taking their own lives there at a rate of 50 to 100 deaths a year. The site holds so many bodies that the Yakuza pays homeless people to sneak into the forest and rob the corpses. The authorities sweep for bodies only on an annual basis, as the forest sits at the base of Mt. Fuji and is too dense to patrol more frequently.