Crews who fly the 757 also fly the 767, and several 767s fly nonstop from US cities daily, like SFO, PDX, and HNL. So, crews get over to NRT via the nonstop flights, and then spend up to 10 days over there (up to 12 day total trips) doing turns or one leg days to Guam, Saipan, Palau, Beijing, and Shanghai. I think SEA guys fly nonstop to Osaka and Beijing, then off to Narita or Guam, and then back through NRT. The LAX 75/76 guys usually hit Japan through Hawaii first, usually laying over in HNL first, then rotate back and forth to Hawaii to Narita, Osaka, Nagoya, and Fukuoka. But, the guys who get to see the most Asia on the 75/76 are the SEA, LAX, and MSP pilots. The trips can be senior, some people want to commute once per month, and a lot of time off between big trips can be had. But, not everyone wants to be gone that long, so looking at the bid awards, the 12 day trips can go fairly junior in some bases.
Other planes that have up to 12 day trips to Asia are the 744 pilots and A330 pilots. The 777 pilots don't have the longer trips, with a 6 or 7 day trip the max for those guys. Certain planes see certain cities, too, like Singapore currently only sees the 777 via NRT.
Bye Bye---General Lee