[blimp]

i take for granted that u will arrive in japan with some sort of visa allowing you to stay longer than 3 months, which means that you can't use the JR Pass.

there are campaigns every now and then flying osaka-tokyo for 10,000 yen. however the most common leg for that flight is hanada-itama (in simple, the domestic airports for tokyo and osaka)

then again, the simplest, as MMM pointed out, is just to fly in to Osaka (KIX). if you are flying from Europe, there are not that many companies that do fly to Osaka these days. air france and KLM might be the only once, i am not too certain on this one though. With JAL and ANA you can always get a connecting flight form Narita to Haneda, it's usually the same price.