Domestic - Int’l departure from Okayama

I'm going to be travelling to Japan with my family. Departing from Okayama Airport, transferring at Haneda and then from Haneda to Osaka Airport for the trip back to the US. I have a couple of questions, first is how early should we arrive at Okayama Airport and second, since it's a domestic flight to Haneda should we expect to go through a full departure and then go through immigration?

Thank you!

I have a couple of questions, first is how early should we arrive at Okayama Airport

Since it is a domestic flight you can theoretically check in your luggage as late as 20 minutes before departure. But just in case something happens along the way, I recommend to arrive at the airport around an hour before departure.

and second, since it's a domestic flight to Haneda should we expect to go through a full departure and then go through immigration?

You will go through immigration at Haneda Airport.

It seems OP goes from HND to KIX and then to the US, so would pass immigration at KIX.

Thanks for the correction.

Collecting airline miles? Kansai Airport is just a 2 hour train ride from Okayama.

Probably OP just searched for flights from Okayama to the US and that's what showed up. I wouldn't be surprised if it was cheaper than a ticket from KIX either; airline pricing is weird...

It does seem odd to go OKY to HND to KIX.
Can�ft you fly OKY to KIX, or take the train between those two places, rather than go via Tokyo and have two airport changes?

I highly doubt there are OKJ-KIX flights. It's just too close for any viability.

Take the Shinkansen from Okayama to Shin-Osaka station and then transfer to the Haruka train for Kansai (KIX) airport. You will be there in under 2 hours for only 8000 yen (or potentially free if you have a rail pass).

There is no possible way a flight all the way to Tokyo and back to KIX, with a transfer, can be faster or cheaper than that.

Or, there are more flights that depart from Tokyo to USA than there are from Kansai, and they are about an hour shorter in general. So if you really want to fly, just depart from Tokyo rather than Kansai. That will save you a connection and a couple hours (or more).