<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by RTW4:
LHR-SIN-HKG-NRT-HKG-NRT
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Once you get back to NRT that will be the end of the trip. You cannot backtrack to/from your point of origin. Also 2 stopover rule applies in continent of origin.
Looks like you can add on another couple of segments in Europe.