A 42-year-old man was found dead on the side of a flooded road early on Monday in Kitami City, Hokkaido, after his abandoned car was discovered nearby.
According to National Fire Department, three people have suffered serious injuries including a 58-year-old woman, who remains unconscious. Rescue teams saw the woman clinging to a roadside guardrail but she slipped and was later recovered 600 meters away.
Hundreds of flights have already been canceled and parts of the country have been left flooded after typhoons Mindulle and Kompasu caused strong winds and pouring rains.
The Japanese Meteorological Agency
was forecasting floods, heavy rains and high waves in dozens of provinces across Japan on Monday, while Prime Minister Shinzo Abe's office
warned of landslides.
More than 380 flights had been canceled as of Monday morning, according to local Japanese media, while 105 express trains were canceled.
Currently tearing past Tokyo with wind speeds of up to 110 miles per hour (about 180 kilometers per hour), Typhoon Mindulle made landfall on Monday at about 1 p.m. local time on the country's east coast.
At least 10,000 people were told to evacuate in Kanagawa prefecture ahead of the storm's arrival. That advisory has now increased to 100,000 people.
Mindulle is projected to pass over some of Japan's most populated areas, including the cities of Tokyo, Yokohama and Sendai. Up to 15 inches (400 millimeters) of rainfall is expected in 24 hours in the Tokai area, north of Tokyo.
The second storm's landfall comes less than 24 hours after Typhoon Kompasu
hit the Japanese island of Hokkaido late Sunday night, forcing thousands of locals to evacuate after the Tokoro river flooded.
Nearly 6 inches (149 millimeters) fell in the city of Asahikawa, on the island of Hokkaido, as the storm ripped across the island.
It has now been downgraded to a low pressure system, hovering off the country's northern coast.
On the opposite side of the country, Tropical Storm Lionrock is forecast to develop into a typhoon by Thursday, avoiding much of Japan but heading for Okinawa in the East China Sea.
That typhoon is due to pass by Japan's southern islands on Thursday morning.