Upvote:5
ANA and United are partner airlines in the Star Alliance. You should be able to check your baggage all the way through from Taipei to Houston.
If you have one booking/ticket they will do it automatically. If you have two separate bookings, then you will need to show your second ticket so they can enter the necessary baggage tracking details.
If by some weird chance that you can not check your bags through, then you would need to follow the signs for immigration, enter Japan (visa rules dependent on your nationality), claim your baggage, head up to check in, check in, then proceed through immigration back into the departure area. There is no "transit" short cut.
Upvote:6
I returned from my trip and I was able without a visa to pass security through the transit section in Narita, ANA was able to send my luggage to my final destination even if I had a connecting flight with United Airlines in Narita with a different booking.