When we were first looking into making an ofuro, one of the things we considered was pouring one out of concrete. The good thing about concrete is that the material is cheap, and with a little hard work it lends itself well to the DIY approach. We quickly bagged the idea because there is no possible way our floor could support the weight. This morning I stumbled across an old post on Apartment Therapy with a gorgeous DIY bathroom built for under 3k which includes a concrete ofuro. The soaking tub only cost about $200 according to the owner splat girl. She did mention that it was a lot of work though. Check out her flicker photo set and the Apartment Therapy post.