I'm planning a trip to Japan next year and I'm making a list of routes and planes to tick off my bucket list.

What is currently the longest domestic flight in Japan?

Which among the longest routes has domestic first? Or even better, always gets an international wide body subbing for the domestic planes?

I have never flown on the 787, so that will be on my list. I would think both ANA and JAL use their 788s and 789s domestically? I would not suppose that 787-10 flies domestically?

I've been on the A350 multiple times, although it would still be interesting flying it within Japan. Likewise with the A380.

Thanks for any info!