I would be getting the JR Rail Pass for myself, wife and elder son. I have another son age 5 so i wont be buying the pass for him. If i travel on the Nex (all reserved seats) from Narita to Tokyo, will i have to buy a separate ticket for him or he can sit with us for free. I understand that he may have to sit on our laps if there are no empty seats, but is that even allowed on the Nex?

Another question is that while the three of us can sit on JR buses and its covered by our pass, does my 5 year old need to pay for any trips on JR buses?

Small children up to the age of 6 travel for free provided they don't occupy a seat. This applies to all trains, including the Narita Express. If the seat next to you is vacant, then of course, there is no problem if he sits there. But even if there is no vacant seat, I think one adult and two children can sit quite comfortably on two seats if you raise the central armrest.

Anyone knows abt the ruling for kids age 5 on JR buses? Do they also travel free?