Being doing some research into the Japanese fisheries marine CW transmissions, finally sorted out a page in Japanese with some locations and frequencies. Hope R4002 gets some benefit from my translating as he commented on the fact sheet being in Japanese...
Usually they transmit a brief warm up session on the half hour before the main transmission on the hour. You will often pick up the word "Gyogyo" in the warm up and main transmission, this translates to "Fisheries" in English.
The ones in bold have been heard by me in the past week.
A good indicator is the Korean Telecom beacon/marker on 22.611.5MHz CW which is 24 hours, 3Kw to log periodic antenna near Seoul. It sends the following: "CQ CQ CQ DE HLF HLF HLF QSX 22MHZ K". If you can hear that then the Japanese fisheries will be a good possibility.
22.533.0MHz CW JFE Okinawa 800w transmitter
22.599.0MHz CW JFC Misaki, Kanagawa 2Kw transmitter
22.599.0MHz CW JHA Ibaraki, 500w transmitter
22.599.0MHz CW JHC Chiba, 1Kw transmitter
22.605.5MHz CW JFG Shizouka 1Kw transmitter22.605.5MHz CW JFH Mie, 2Kw transmitter
22.606.5MHz CW JFM Muroto, Kochi, 2Kw transmitter
22.642.0MHz CW JFR Nagasaki, 2Kw transmitter
22.642.0MHz CW JFR2 Nagasaki, 2Kw transmitter
22.642.0MHz CW JFX Kagoshima, 1Kw transmitter22.681.5MHz CW JFS Aomori, 2Kw transmitter
22.681.5MHz CW JFT Kamaishi, Iwate, 500w transmitter22.681.5MHz CW JFW Iwaki, Fukushima 1Kw transitter