Where can I see Hokusai's Great Wave today?

There's a Hokusai museum in Tokyo where it's on permanent display. You can also catch a sumo match nearby.

https://hokusai-museum.jp/?lang=en

And another one in Haifa: https://www.tmja.org.il/eng/Collection/Ukiyo-e_Woodblock_Pri...

The Sumida Hokusai Museum is almost entirely a display of replicas. They are very upfront about being a “learning” museum - they do hold the original prints but display them in rotation. We were there last year and there was exactly one original print on display (in a back corner of the special exhibit room); it was one of the “36 views” but not one of the uber-famous ones.

As far as I'm aware this has never been on view. You can probably request to see it privately. (I'm the creator of the site in the OP)

I think it's on view permanently, except when the museum is closed (as it is now).

I can’t say anything with regards to when it was made though.

Generally, these are so susceptible to fading that they are not displayed for more than a short period of time. My records go back to 2015 so it could have been on view at least a couple of times over that period. I last emailed them early-2023 and it was not on view that year, and was told it would not be in 2024. Which brings us to 2025 and we know how that's going. That said, this imprint at Tikotin Museum of Japanese Art is marked as an original.

While most the time they display replica, sometimes they do show the original, like for example right now. Sadly no live sumo in Ryogoku, the next tournament starts this Sunday in Nagoya.