Tokyo Typhoon Nabi lashed southern Japan and South Korea on Tuesday, killing five people, injuring dozens and forcing tens of thousands to flee their homes.
At least 15 others were reported missing as waves driven by 78 mph winds slammed into coastal barriers and storm surges flooded seaside towns.
The typhoon made landfall and traveled up Japan's southernmost main island of Kyushu, weather officials said. Heavy rain and wind also pounded the neighboring island of Shikoku.
By late evening, the storm had moved into the Sea of Japan and was heading northeast over open water.
Nabi, which means "butterfly" in Korean, grounded hundreds of flights, blocked train and ferry services and closed highways, stranding tens of thousands.
"The wind and rain were so strong earlier this morning, I could hardly walk - I couldn't leave the building," said Mitoshi Shiroi from his flooded grocery store in Kyushu's Tarumizu town. "The water just keeps on coming in from under the door."
Japan sent 70 soldiers to fortify barriers, assist evacuees and provide other help in storm-hit areas, said Chief Cabinet Secretary Hiroyuki Hosoda.
The storm killed at least five people and injured 53, a National Police Agency official said on condition of anonymity, citing agency rules. Another 15 were missing, he said.
Nabi was expected to move northeast and become the first typhoon to hit South Korea this year.