Maybe you could find a way to break up the trip. Check with airlines to see if they have stopover fares, via which you may be able to spend some time in a destination in between. For example, if you are starting in Boston, you may be able to have a stop in Seattle, San Francisco, or Honolulu.

Some airlines promote these and some do not. You may be more likely to get one of these deals if you fly via a Japanese airline like ANA or Japan Air.