Join Date: May 2008
Location: IAD or elsewhere
Programs: UA 1K, LH M&M, AA EXP, Marriott Plat, Avis NotLast, Hilton Gold, Hertz 5*
Posts: 655
Another option
Try breaking up your itinerary - you can do SFO - ICN (round trip) for ~ $1000 on UA or SQ, and have a separate itinerary ICN - NRT (round trip) for ~ $376 on UA.
Flights to / from Korea are significantly less than Japan because of the sinking Won. Ironically, you can go on UA to Seoul (ICN) via NRT for $100 more. The above flights are nonstop.
Good luck, and enjoy Tokyo!