The Asahi Newspaper is reporting (2005.05.09) that the famous tuna auctions at the Tsukiji Metropolitan Fish Market in Tokyo is off limits to tourists because of the "bad behavior of foreigners." Speaking as a frequent photographer there -- I can agree: foreigners were getting in the way of the merchants who were there to make a living, but so were some Japanese, it's just that we blended in more. The foreign visitors that I saw when I visited were both in the way of traffic and using the flashes on their cameras during auctions, which is very distracting. Visitors to the tuna auction will now need to get a permit from their local city or merchant association. The outside stalls in the Fish Market remain open.
The original article:
See my Tsukiji photography here. I did caution visitors in my article that they needed to be on their best behavior. Tsukiji's tuna auction has been closed before and only recently opened up to visitors again. I expect it will be several more years before we'll get free access again.
For more information and details on what type of permission you will need, please contact the Tsukiji Market directly: http://www.tsukiji-market.or.jp/