The Luggage
The more hotels, the more lugging of the luggage. Lugging wheelie luggage on flat sidewalks isn't so bad, and lugging on escalators is do-able.But then there are the endless subway stairs of doom, and you can't always count on the green power ranger to help you.
My plan: 1 small suitcase, 1 "carry-on" size bag. They are stackable. Enough capacity for Lottsa $hopping Loot, and a minimum of clothes.
Hand Washing Paraphernalia
Some bathrooms, especially train stations, might not have soap. Or anything with which to dry your hands. And possibly no toilet paper. I think the logistics of keeping a stocked bathroom might be a little impractical when it's constantly in use by a super dense population.
I never encountered a no-TP zone last time, but it doesn't hurt to grab those little packs of tissues the girls hand out on street corners.
We brought hand sanitizer last time. That got some use. But I like the clean feel of really washing my hands. This time, I'm going to look for paper soap:
Packs of tiny soapy papers. Hopefully not too hard to find. Also, it might be nice to dry my hands like a human, and not like a crazy flailing bear. The solution: the half towel.
I think they may also be considered "towel handkerchief". Anyway, kinda handy to keep in your bag for this purpose.