Product designer Masatoshi Saeki's Tenmoku cup. It has a simple design and is very beautiful. I love using similar pieces from this series, but I haven't had much opportunity to use the cup, so I'm putting it up for sale. It's not unused, but it's in good condition with no cracks or chips. I think it might be a work from the late 70s to the 80s. Purchase without comments is welcome!