So we went to the Met today to see Hokusai's big wave (see below) and...it's not up. It's not on tour either. It's just...put away. Spoke with someone in the department (the info desk lady was kind enough to let me use the in-house phone -- Japanese art is at ext. 3838) and the nice lady who answered confirmed its absence from the floor, and then said she didn't know when it would be on display again, that all she could tell me was that they have a large collection, and that only part of it is exhibited at any given time, and that they rotate pieces every 3-4 months. I can just "keep calling" to ask if it's up before scheduling my next visit.