Oshino Village is used be a lake called Lake Utsu for long time ago. When Mt. Fuji erupted, Lava from Mt. Fuji coverd north part of Lake Utsu. Then, the south part of Lake Utsu (宇津湖) becomes Lake Yamanaka, and covered area became Oshino Village. The spring spots of Mt. Fuji were still left in the same spots. So, eventually water spring in Oshino Village, and they were called Oshino Hakkai.
Because Mt. Fuji is believed as spiritual mountain, the water of Oshino Hakkai was called “The spring of God.” Those believes created many local legends. Now, Oshino Hakkai is one of the National Treasure of Japan, and 100 best water of Japan.