What it is
Toyosu Market is a Tokyo-run wholesale market handling seafood and produce. It's said to have taken over the functions of the former Tsukiji market when it relocated here in 2018, and a public walkway has been set up for visitors. From the walkway in the seafood wholesale building, visitors can watch the tuna auction, and there's also an area of restaurants and shops open to the general public.
Tips for visiting
The deck offering a close-up view of the tuna auction is said to require advance reservation and a lottery, so it isn't something you can simply walk into on the day. The general visitor walkway is said to be open without a reservation, though viewing is limited so as not to interfere with market operations, and tours can be suspended entirely during especially busy periods. The restaurant and shop area is said to be set up with visitors in mind and can be enjoyed without a reservation.
When to visit
General visiting hours are said to run from early morning into the afternoon, but since the tuna auction happens early in the morning, you'd need to arrive early to see it. Being a working market, tours can be restricted during busy periods such as year-end, so it's worth checking the official site for the latest visitor information before you go.
Besides the visitor walkway, a garden-like plaza is said to be maintained on the roof, known as a rest spot with views over Tokyo Bay and the Rainbow Bridge. Many restaurants inside open from early morning, and many visitors are said to enjoy breakfast there while taking in the market's energy. Alongside a tour, many visitors are said to also enjoy the adjacent Senkyaku Banrai facility, which has a hot spring bath and souvenir shops.