International to Domestic transfer at Narita

Look for another flight with more time between flights.

Are you sure your flight to Itami is from NRT and not from HND?

You do need to do immigration and collect bags and go through customs in Narita. Minimum connection international to domestic is 75 minutes. If its all booked on one ticket even if you misconnect you'll be accommodated on the next AVAILABLE flight. If on separate tickets you'll be subject to the fare rules of your flight to itami, which may mean you are on the next flight or may mean you are buying a new ticket, or something in between. Best is to have a single ticket for your entire itinerary.

By the way, if Osaka or Kyoto is your desired destination, there are non-stop flights from San Francisco to KIX - way easier than a change in Narita.

Looks like you're arriving on ANA at 3:25p and connecting on ANA's 4:45p flight to ITM. Same terminal, so 80 minutes should be okay. And if you miss that connection, they have another flight at 5:55p.

Of course, you could have just booked the 5:55p connecting flight and not worry about it.

Thanks rkkwan, KimJapan, and hawaiiantravelleler. I was taking this route mainly to save a couple hundred dollars. My flight was the LA-NRT Continental flight reaching NRT at 4:35, and the connecting flight is (on the same ticket) NRT-ITM at 5:55. Now I am confused whether to spend 200 more dollars or just hope the airline gives me a connection if I miss the first one, since it is all on the same ticket.

Same ticket you are protected. But if you miss then the caveat is next AVAILABLE flight - so if the flight is sold out you wait.

There's no more NRT-ITM flight after the 5:55p. You'll be busing to HND and flying out of there, if you miss it. But chances are you can make the 80 minute connection. You are flying United for SFO-NRT and ANA for NRT-ITM, despite having Continental numbers.