Just a quick point if you're packing light or need to do laundry in Japan.
Some hotels will have coin operated laundry but some (including our current Tokyo hotel) do not.
You need to look for (or ask your hotel front desk) where the nearest 'coin laundry'. Not laundromat or anything else. Coin laundry.
Some require you to add detergent, some don't - we packed a few travel detergents with us to cover all bases. Also the dryer probably will not completely dry your clothes- be prepared to hang some things in the bathroom to dry.