American Airlines currently has a half off sale using miles to fly from SFO-HND (Tokyo, Jp) which cuts the RT Business Class ticket cost to 50,000 miles.   LINK

Reading into this promotion more carefully, the best deal obviously is the 50k in business as Business Class tickets usually run in the 3-4k+ range.  A coach ticket at 30k points for ~$1000, so purely on a point value basis the Business class ticket is a better deal.  Don’t want to go to Japan?  You can also purchase other tickets from Japan to elsewhere in Asia.  Just make sure you give yourself a few hours (or a day) between flights just in case your first plane is late.