While NRT is a very favorable place to start a DONEx it is not as relatively favorable for a AONEx. Instead you might want to consider Qatar. An ex-DOH AONE3 is currently GBP3480 while an ex-NRT AONE3 is GBP3820 (whereas the relative advantages are reversed for a DONE3- NRT being about GBP100 cheaper). It would seem that it might be cheaper for you to go from LHR to DOH than to NRT. And talking about tier points, being in DOH, you can do the classic DOH-BAH run (90 miles) and pick up 180 TP each way in First-- obviously you do it on a separate ticket instead of wasting AONE segments. On the possibily negative side, it would restrict your Europe stopovers to 2, rather than restricting the Asia stopovers to 2.