It’s about 10 hours LAX- NRT and 3-4 Hours NRT-GUM. The layover at NRT is around 1-2 hours. It is about 5 hours LAX-HNL and 7 hours HNL-GUM. The layover is about three hours.

For the return I actually prefer GUM-NRT-LAX over GUM-HNL-LAX. You depart GUM around noon and get to LAX late morning. The timing of the longer lie flat segment is after a shorter flight to NRT and you don’t have to deal with the Hawaii tourists. NRT also has better lounges and souvenir shops, etc.