Thanks sooo much guys for the helpful tips. I felt the same, transferring from NRT to HND in Tokyo Traffic after a 11 hour flight from Europe is something I would like to avoid. The connecting time is 5 hours, though enough for the trek, not worth wasting the time in my opinion to to avoid LH C. I man LH C, though not the best C product but it is still pretty descent, plus for a cheap reward flight, can't really complain

Having taken all into account, we made the booking, itinerary looks like this:

LHR - FRA - KIX all in C on LH
NRT - ZRH - LHR all in C on LX

We are still in Osaka for 4 nights then make our own way to Tokyo on Shinkansen before heading back from NRT. Managed to get two C tickets on LX on the way back pretty happy with it. all in all 52500 miles + £360 + £500 TAX pp. Did I do well??