STORY: TV Tokyo footage from Saturday showed heavy rainfall and strong winds hitting the southern island of Amami Oshima as the typhoon approached.
The 14th typhoon of the season, classified as a super typhoon by the U.S. Navy's Joint Typhoon Warning Center,
has the potential to be the most destructive tropical storm to strike Japan in decades.
The JMA said it could bring record rainfall, and warned of the risk of landslides and rivers overflowing.
The storm is forecast to curve east and continue up Japan's main island of Honshu early next week before moving out to sea by Wednesday (September 21).