Originally Posted by
tangoll
1. For travel over long distances, go Skinkansen, about Y15,000 Tokyo to Osaka, if I remember correctly.
You might want to look into a cheap flight to Tokyo (Starflyer etc) and then Shinkansening your way back, which would probably work out cheaper. How are your girlfriend's flights laid out -- can you arrange an open jaw so she flies into Tokyo and out from Kyushu, or vica versa?
You should also plan a stay or two at a Japanese ryokan or onsen (hot springs), and for better onsens, you're looking at 20,000 - 30,000 yen per person per night, inclusive two meals (dinner and next day breakfast).
YMMV, but I've generally found ryokan in the 10-15k yen/pp range to be more than adequate. Even fancier places often have promo rates in this range if you're traveling off-season and can book deals off their websites or Japanese booking engines.
Or you can just go to JTB and have them arrange the whole itinerary for you.
I have a hard time imagining that this would be cheap or enjoyable, eg. they won't book you into any hotels except the few mass-market operations that certify they're gaijin-compatible.