Your seats will be reasonably comfortable, as much as a non-flat can be on that length of flight. I usually try for Row 1, as I don't like a seatback intruding on my space. Of course, others like the extra storage space in the foot areas of rows 2 and 3.

The lounges in LA and HNL are simple. No alcohol or food, aside from chips. I've not been to KIX, but their lounge in HND is better stocked with real food and alcohol. There was a shower in the HND lounge, IRRC, but definately none in HNL.

On your flight to/from Japan, you will get slippers, eyes shades, etc. No PJs,