Several times we bought prepared hot meals from a supermarket or a kiosk, which we ate in a nice place nearby, preferably overlooking the sea or near a temple. Also very handy are the can machines offering cold and warm drinks, which are found everywhere on the side of the road. We travelled with Finnair to Japan, because they offered the cheapest return fare from Schiphol, Amsterdam. We had wanted to fly direct to Osaka and leave from Tokyo with KLM, but this was not possible, because they wouldn't take a tandem. So we decided to fly to Osaka and to take a ferry to Tokyo to visit Wim's sister and her family in Yokohama.
Ferries are a very good option for travelling inside Japan.
The decision to fly Finnair via Helsinki turned out to be a mistake. During transit in Helsinki, we saw our tandem being maltreated during off-loading from the plane. A stout Finn threw the bike from the plane in the baggage-cart and put a pile of suitcases on top of it. We had thought it was clever to pack the bike in see-through plastic, but apparently this didn't make any difference.