We're spending a week in Japan next month as part of a RTW trip. Hotels are booked, all done through Trailfinders, the plan is a couple of nights in Tokyo, two nights in Takayama, two nights in Kyoto then back to Tokyo, all by train.
We have some ideas of things to do but are there general things to bear in mind, especially wrt etiquette!
hi I lived in Tokyo a few years ago. What an adventure. Without specific questions it's difficult to know where to start but I would say be prepared for the fact that NOONE speaks English. I would recommend getting a phrasebook/cd and learning some absolute basics, it will help an awful lot. However I would have thought the Japanese would be extremely welcoming to a "gaijin" family - rare to see gaijin tourits with children there. Travelling by train will be easy. Weather in August is horrible, sorry. Cloudy rainy and very humid. You may be lucky though as it normally improves dramatically early September.
bring socks!! if you are hoping to eat in nice/upmarket traditional restaurants, you will need to take off your shoes - so you will be exposing your feet, or holey socks - neither of which are desirable!!
If your children aren't too adventurous foodwise then eating could be a bit challenging. As mentioned above, hardly anyone speaks English. Menus are often just in Japanese, although they do like putting pictures of the food on them. I am veggie and, even with this written down on a card that I handed over to every waitress, it caused some problems. If I tried to ask for something without the meat/fish they got really flummoxed. So you might have difficulties in traditional restaurants asking for a more child friendly version of a dish. There are a lot of western restaurants around and we would alternate Japanese food one night with eg pizza/pasta the next.
Also, we seemed to get accosted everywhere we went by school children on trips who had been tasked with practising their English with tourists! There didn't seem to be many foreign tourists around so the whole class would want to speak to us. Travelling with children you might get that even more!
Not sure how old your children are but they might love the fact that there are vending machines EVERYWHERE - you can buy noodles and shirts/ties at the hotel ones, they are on every street corner for drinks and also lots on trains!
The trains are fantastic by the way! But the Tokyo metro and local trains get horrendously crowded (and we are used to the London underground in rush hour!) With children you might want to try to avoid them in the rush hour.