*UPDATE* - This great deal with Alitalia is available once again (same as the flights to Seoul we updated earlier today). Again you may consider very cheap return flights to Japan ex various European countries. If you dont mind there is longer layover during your trip to Tokyo you may book round trip flights already for €360 or £281!
This possible error fare deal with Alitalia is available in travel period till 30th of June 2015.Max stay in Japan 1 month. This promotional deal is valid for bookings made till 31st of March 2015. All these European cities are easy to reach either by bus or low cost airlines. To check your connection possibilities from your home town directly you may check through Skyscanner. Cheap accommodation in Japan is possible to compare and book here.
Booking samples
Berlin- Japan from €375
Dusseldorf - Japan from €376
Munich - Japan from €380
Frankfurt - Japan from €389
London - Japan from £281
Brussels - Japan from €402
Amsterdam - Japan from €393
Budapest - Tokyo for €360
Switzerland - Tokyo from €391
Vienna - Tokyo for €389
Travel dates to Japan are the easiest to check via Ebookers here using +- 3 days searching too.
Booking sample of cheap return flights from Europe to Japan for €360 here. In this case you would be flying from Budapest to Tokyo on 30th of April and returning from Asia back to Europe on 15th of May 2015.