Maybe the new EuroBonus earnings are already stating to pay off?

Might be incidental as well...
Anyway, it's also my experience that flights to NRT or HND are always completely packed (also with LH and LX, by the way) and that affordable fares are hard to find. I booked flights to NRT with SK for March during the last by one sales (when EB earnings were still good) and then it was already puzzling to find two decent fares for the whole trip.