The typhoon made landfall on Sunday evening near Kagoshima in the southwest of the country and brought strong winds and heavy rains to the big island of Kyushu before moving northeast along the coast of the Japanese sea.
Having gradually lost speed, it was downgraded Tuesday morning to an extratropical cyclone.
But in Kyushu, the storm toppled trees, shattered windows, swelled rivers and dumped a month’s worth of rain in 24 hours on parts of Miyazaki prefecture, where two deaths were confirmed.
Government spokesman Hirozaku Matsuno said two more people were found “without vital signs”, a term used in Japan before a death was officially certified by a doctor.
The toll could rise further as authorities were checking to see if two more deaths were related to the typhoon and they were also searching for a missing person, Matsuno added.
In addition, at least 114 people were injured, 14 of them seriously, said the government spokesman.
As of early Tuesday, around 140,000 homes were still without power across the country, mostly in Kyushu.
Typhoon season peaks from August to September in Japan, where it is marked by heavy rains that can cause sudden floods and deadly landslides.
Scientists estimate that climate change is increasing the intensity of storms and making extreme weather events more frequent.
