Originally Posted by
Twickenham
But if you're on one ticket, surely any bag you check will be checked through? You shouldn't have to handle it at all until you reach your final destination.
All passengers must go through customs at HND, thus checked bags retrieved and re-checked / dropped off at domestic check-in at the international terminal.
If OP is significantly delayed and misses the inter-terminal bag drop deadline, he must take the checked bags on the shuttle bus / train / monorail and drop those bags at the domestic terminal, where the lines are much longer though there is priority line if he knows to find it.
Or if he is really really delayed and cannot possibly make the original connection, he rebooks at the domestic counter inside the international terminal.