I can't see any reason why not. What would be a materially shorter routing? Staralliance.com shows routings via NRT at 9,606 miles but also via Europe (FRA, ZRH, MUC etc) at between 9,400 and 9,600 miles.
One way Z7-Z3 would be 50,000 miles + taxes or 25,000 miles + £170 + taxes in Y or x1.5/2 times in J or F. Good value....