It's in Kyoto and currently under renovation. We stumbled across it during our Far East visit earlier this year. You can go round the perimeter of the building but in reality you can't see very much. Sadly I'd no idea thst it was there prior to the visit otherwise I would have written and asked if it was possible to be shown around the worksite...permission not necessarily granted but it's the way they like to do things.
Struth! That place has changed. I lived just behind the car park that you can see in the background for a short time when I was over there and that dock area just behind the Art Gallery was pretty run down then. Bet it costs a pretty penny to live there now.