Currently, I have four $150 type B vouchers from my last VDB. My girlfriend is coming to visit me in LA from Nagoya, Japan over winter vacation, and I would like to let her use the vouchers. I noticed that vouchers are only good for UA metal flights. However, there is only one way to travel from NGO to LAX, which is flight 830/831 via SFO. And the flights are already full for both ways (12/25 and 12/31) at this moment. I did a search on UAL.com, and all the itineraries include partial code-share flights with NH (via NRT). Is there any chance for me to use the vouchers with itineraries? If not, what is the best way for me to do? Fly from KIX instead (two hours train ride from NGO)? I appreciate if you can enlighten me on this issue. Thanks again.