Narita is generally the best airport in the system for getting priority bags out first. There is also a baggage agent (BA) walking around the carousel and if you ask the BA, they can check you name or scan your stub and tell you precisely wear on the conveyor system your bag is. UA's BAs in Tokyo are incredibly responsive. One time, I was on crutches and they offered to help carry my bags out to the bus, parking lot of wherever I was going. They are very good.