A local fisher keeps looking for passengers who remain missing a month after their sightseeing boat sank off Shiretoko Peninsula in Hokkaido, northern Japan.

The "Kazu I" sank on April 23 with 26 people on board. Twelve are still missing.

Kosaka Akihiko, a fisher for 45 years, has been leading a group of local fishers and others searching for passengers since the day after the accident.

He continues to look for them on his way to and back from fishing sites even after the high fishing season started in early May.

Around 6 a.m. on Monday, Kosaka headed out to sea, passing close to the accident site, and returned to the port two hours later.

Kosaka said he hopes to find even one person.

He said he wants to know the cause of the accident, and will continue to look for the missing.