busy season.
In December, Japanese are always busy and in a hurry(I'm not, though).
From 15th of Dec. to 17th of Jan, the government of Tokyo Metropolitan
decided not to open the auction to the public.
I guess it's because most of fishermans are rough-natured persons and it's dangerous:P
So, if you have a plan to go there in that period, you don't have to get up so early.
Of course, the other shops and restaurants are open for us.
The best time to go there will be around 8AM and have some fresh sushi for your breakfast;)