Transfer time in Tokyo station
 

I am going to be traveling to Narita Int'l. airport. I will then be getting on the Narita Express to Tokyo Station. I think catch a Shinkansen train to Kobe. Can you help me two things? First, how long will it take to get from the Narita Express train to the Kobe train? Second, I will be in a green car. Will there be room for a large suitcase on the car? I will be on a train around 3:00 PM.

Just used Shinkansen from Tokyo station and travelled to Narita on N'Ex. Airport train will arrive at fourth basement of Sobu line platform (3 or 4). Take an elevator to the street level and use the connecting corridor to Shinkansen on the far side of the station. I'd allow up to 10 min. Though 3 pm isn't yet rush hour the station is always busy with people and you will struggle with your large case, as there are still some steps to negotiate. I suggest you get yourself a smaller case with wheels or get your case sent directly from Narita to your hotel overnight. There is a counter for delivery service just as you come out of customs. All luggage compartments at the end of each car have been sealed off as a security measure and you will have to take your case to your seat. There isn't a lot of room but more in the Green car. You can hump it on the overhead shelf but I wouldn't try if yours is heavy.

We allowed 20 minutes just to play it safe since you can get a bit lost. We made it in much less time but I'm glad we had the 20 minutes for my sanity.

Re: the large suitcase. Your best bet would be to ship it ahead to the airport. It costs about $20 and works like a charm. Also there aren't a lot of escalators or elevators in Japan train stations.

Definitely agree that if your suitcase is large, use the delivery service and have it sent to your final destination in Kobe. It is fast, reliable, and convenient. Same thing on your return--send it to Narita ahead of time and it will be waiting for you at the shipping company's counter ready for you to simply pick it up and check-in. Did it on my last trip to Tokyo. You won't have much leg space with a large suitcase.