I have been 4 times in last 6 months.
1 time was QR
2 times I used BUD-LHR-[FRA]-HND by JAL (I had Japan visas) then NRT-ICN out and QR back.
Last time I did the AY option but with a start/finish at AMS to keep cost down.
I just started planning my October trip - so please share any good finds...