Upgrading reward tickets
 

When I booked my ticket from sjc-nrt round trip, there were only economy tickets available. So we flew to japan in economy, however today when I checked there web, there are 2 businesses award tickets available. I called their call center and was told that because I had completed 1 segment of my booking, my reservation cannot be changed. I can't upgrade from economy to business for nrt-sjc leg. Is there any hope? Please advise :)

Unless you booked a business class award in advance, you cannot change from economy to business class on an ANA award:

"The airline, passenger, sector, route, and service class* cannot be changed."

Thank you.

If you have enough miles, and want to make another trip to Japan within a certain period, you may change existing NRT-SJC to some date, then book another award such as

NRT-SJC//SJC(or any N.A airport)-NRT(or any JP airport)

or RTW award (or any award which starts from NRT-SJC, then return to Japan)
NRT-SJC-RTW-JPN

we just gave up, so 2 of us were in business, and 2 were in economy. The flight was not full, and I saw at least 10 empty business seats :)