Typhoon Haishen is expected to intensify on Sunday, bringing heavy rain, storm surges and winds of more than 160kmh.
It will move past Kyushu on Sunday, and is expected make landfall in South Korea on Monday.
It comes days after Typhoon Maysak, one of the strongest storms to hit the region in years.
The latest typhoon has led to the closure of factories, schools and businesses across western Japan. Hundreds of flights and train services have also been cancelled.
Japan's government will be holding an emergency cabinet meeting on Sunday to address the storm.