The only domestic Japanese flight that I took was from Kobe to Sapporo on the Hokkaido airline AIR DO. It was a one class service and it was excellent, a really good flight. Soft drinks were offered with a small packaged snack AFAIR, but upon reflection it's possible that there was no snack. Definitely would like to do AIR DO again. My flight had a NH flight number, so I don't know if AIR DO fly under their own brand. Thanks for the trip report, it's really great.