Typhoon Toraji made landfall on the southern edge of Kyushu early Wednesday and was expected to march northeast, prompting storm warnings chiefly for the southern part of the island.
It was the first time in around six years that a typhoon has struck Kyushu directly, the Meteorological Agency said.
The agency issued warnings for landslides and flooding as southern Kyushu was forecast to receive 300 mm of rainfall in the 24 hours to 6 a.m. Thursday, including periodic torrents of 80 mm per hour in some districts.
Northern Kyushu was forecast to get as much as 250 mm of rain through Thursday morning.
Toraji, typhoon No. 17 this season, was near Kobayashi, Miyazaki Prefecture, as of 7 a.m. Wednesday, and was moving at around 30 kph, the weather agency reported.
The agency predicted winds of up to 126 kph and waves of 6 meters in southern Kyushu and winds of up to 108 kph and waves of 5 meters in the northern part of the island. Waves of 5 meters were forecast in the Amami region in the East China Sea, south of Kyushu.