Last April I went there.
Fascinating, diverse … and not expensive.
Useful links for those going on their own.
Itinerary planning
Japan | Frommers.com, helps to establish priorities if your time is limited.
Japan Tourism website, with excellent PDF printable guides.
Our itinerary (15 days): Tokyo, Nikko, Hakone, Takayama & Ogimachi, Okayama & Kurashiki, Hiroshima, Matsuyama, Imabari & Shimanami cycling, Takamatsu, Himeji, Koyasan, Osaka, Nara, Kyoto.
Transport
Jalpak The best flights I’ve found and they can get you the japan rail pass
You will need the timetable to plan your trips inside japan.
You won’t need this, but for rail lovers it contains pictures of all stations for all the lines.
Accomodation
Japaneseguesthouses.com : Traditional japaneses hotels aka Ryokans and Minshukus. I strongly recommend to spend some nights in one of them provided you can arrive early enough to take a bath before dinner (usually excellent) at 6. Reliable website.
http://www.japanhotel.net/ Comfort hotels at a very reasonable price. Reliable website.
Other
For cycling lovers Shimanami route, 70 km between Honshu and Shikoku, bridges over the Sea connecting islands.
Kabuki Theater. Be brave and give it a try, what is as traditional as Noel Coward for japanese ears will be as advanced as the most vanguardist contemporary music like Ligeti or Boulez for yours.
Budget
Flights Barcelona – Japan: 700-900 €
two week Japan Rail Pass: 300 €
Accomodation: 60-100 € double room/night
Meals: 7-15 €
