Amami Oshima (or simply “Amami”) Island World Heritage Site (Kagoshima Prefecture) approx. 200 miles south of mainland Japan midway between mainland Japan and Okinawa, relatively temperate water - rarely below 18 deg C (64.5 F) in winter, above 30 deg C (86 deg F) in summer
Nishikomi - Seisui 21 km video A northwesterly wind blows during the winter months. This route runs in a channel at the southern end of Amami, between an island (Kakeromajima) and the main Amami island to its north.
Amanico Ocean Sports (Amami) has a paddling club (as well as their commercial guiding services, lessons, etc.) 395-2 Naze Oaza Asani, Amami, Kagoshima 894-0043, Japan - Asani Beach
Chigasaki Outrigger Club (even if they do not have surfskis - outriggers and SUPers can be a great resource of paddling and downwinding information)