One man was killed and eight others are missing after a fishing boat capsized off Matsue, Shimane Prefecture, on Wednesday morning.
The boat was being towed by another fishing boat because of engine trouble, the Japan Coast Guard said.
A man believed to be a crew member of the 76-ton Daifuku Maru was taken to a hospital but later pronounced dead, the coast guard said.
The remaining crew, seven other Japanese and an Indonesian man, remain unaccounted for.
The dead man has been identified by the coast guard as 54-year-old Yoshihiro Sakamoto of Kotoura, Tottori Prefecture.
Rescuers have found life jackets but have yet to locate the capsized vessel, with bad weather hampering their efforts, a coast guard official said.
The coast guard received an emergency call at around 5:20 a.m. Wednesday saying that the Daifuku Maru had capsized in the Sea of Japan 1.6 km north of Matsue. The boat belongs to a fisheries cooperative in the town of Iwami in neighboring Tottori Prefecture.
It was raining at the time of the incident and a warning had been issued for strong winds and high waves in the area.
The Daifuku Maru set sail last Thursday night to hunt for crabs and was returning to port, according to the cooperative.
The coast guard has deployed patrol vessels and helicopters to search for the missing crew while the transport ministry dispatched three investigators to probe the cause of the accident.