The coast guard said it was towing the boat to safety
A rickety boat carrying 10 men who say they are North Korean is to be inspected by Japanese authorities after it was found drifting off the coast of Hokkaido island.
The wooden vessel was spotted near the town of Matsumae on Tuesday but could not be approached because of rough seas.
On Thursday, the coast guard said it was towing the boat to safety.
Officials said the men on board communicated in Korean via loudspeakers.
They also had a message board which said they were from North Korea and had been taking refuge on an island nearby because of the challenging conditions.
Every year, dozens of boats wash up on northern Japanese coasts.
It is thought their presence may be linked to a reported campaign by North Korea to send fishermen on longer journeys.
It is unclear whether those on board intend to defect, or are simply unable to get back because of the poor condition of their boats.
Vessels are often pushed towards Japan during the winter because of a seasonal wind.
Earlier this week, eight decomposed bodies washed up on a Japanese beach in a small wooden ship - raising speculation they could have come from North Korea.