I would eat and drink at LAX and plan to sleep as much as possible on the plane.

Be sure to bring good noise-canceling headphones. Last time I took a NH West Coast red-eye in C, I got stuck across the aisle from a family with a little kid who was yammering at the top of his lungs nonstop all the way to Tokyo. Earplugs were not enough to block it out; I needed a white noise generator.

Also be aware that there is no arrival lounge at HND unless you're connecting. The shower facility in the arrivals area has been closed since the pandemic started, and the one time I tried to use it after an early arrival pre-pandemic, there was a 4-hour wait to get in. So you'll want to make sure your hotel offers early check-in.