Easy connection. Just take the bus, it's easier.

If op misses the last bus(depart NRT at around 9:30 pm), I guess it's almost game over.

I made it - all hail the winner of the amazing race
 

Alright ppl..... Success!!!!!!!!!

Here is the breakdown... Had a 30 min delay out of Shanghai...at this point i was getting worried... Plane touched down at NRT at 8:45 (last bus is 9:25 remember)... I'm thinking alright... i should be good.... BUT...
we drive a mile down the runway..... by the time we deplane its 9pm.... and I'm in some offshoot of T2 I've never seen before that requires train ride to the main building. So needless to say... i start RUNNING!!! i get on the train.. arrive at the main building at 9:10 or so..... 15 min to go... i get to immigration....and BAM! - over an hour wait.... so i manage to beg my way into the diplomatic line.... by the time I'm through I have 5 min to go before the bus... i run downstairs.. and literally see my suitcase on the belt... i bolt and grab it and make a run for the the bus ticket counter.... buy the ticket...bolt out the terminal...light a cigarette on the run and arrive with 2 min to spare... will i do this again.... no..... but I have a story to tell now at least :)

If you're on NH or (JL?), and you're late and miss the bus, they'll pay for a taxi or hired car (depending on what class you're flying).

Wow. I imagined that any airline would just say that the OP was optimistic to think that he could connect to HND in such a short time on a separate PNR and wash their hands of it.

If the flight's on time you're out of luck but if you miss the bus because the flight is delayed, they'll pay for alternative transportation. For NH, it's a hired car if your in C or F and a taxi if you're in Y.

This is the key. The first airline's liability ended when they delivered the passenger to NRT.

If I were to miss the connecting flight, I would only expect the second airline to book me on a later flight and charge the appropriate change fee and fare difference.

Ya i was on completely different itineraries. It was China Eastern from bkk-NRT... JAL from HND-SFO.... i dont think either airline would have done a thing for me if i had missed the last bus...