Texas Hot spring in Akita Prefecture, Japan Ōfuka Onsen Ōfuka onsen (大深温泉, Ōfuka onsen) is an onsen (hot spring) in Semboku, Akita, Japan. See also Onsen 39°58′17.5″N 140°49′0.9″E / 39.971528°N 140.816917°E / 39.971528; 140.816917