We loved the Japanese food, which was one of the best parts of the trip. My personal favorite was a sushi breakfast at the Tokyo fish market. We went there around 5AM. Didn't try Mos Burger.
The air temp was not too bad for the first part of the week - around 45-50 degrees F. The water temp in Tokyo Bay was a little colder than SF Bay. The water in Tenryu River was colder than Tokyo Bay, but the ocean temp was warmer than the bay and river. My 4/3 with an underlayer and a hood, boots and gloves was perfectly toasty.
Later on in the week, we made a trip to Kyoto and the temperature dropped. It snowed for two days but luckily I didn't plan on kiting those days. Kyoto was a very interesting experience. We stayed and ate authentic Japanese food at a Ryoken (old style Japanese hotel)