Dont waste your jetlag... when your wide awake on the 4am after you arrive, get a cab down to the tsukiji fish market in Tokyo, well worth the visit to the worlds largest wholesale fish market. They'll have tuna auctions at 5am that will have fish going for over $1000 and the whole market will be wrapped up by 9am. Everything that lives in the sea (including a whole lot of animals I had no idea lived in the sea, and I scuba dive) will be on display live for the restaurants/sushi cooks to peruse for purchase and delivery that day.