Originally Posted by
nesnith
It depends. If you are in-and-out of Haneda, then your luggage should be checked through.
If you are flying into Haneda, but flying out of Narita, then you will need to claim your luggage at Haneda, and make your way to Narita with your luggage.
I'm flying in and out of Haneda both times, but I was concerned about the long layover on the return.