Shinkansen magic

Arrived early at the station and saw there was a train an hour earlier than our booked and ticketed train. Can we change the tickets? Is it a long process? Will there be a charge? Will the station staff be unhelpful and bored by the request? If in the UK the answer to ALL the questions above would be yes – if in Japan it’s yes to the first question and no to the rest. 
We asked at the gate and were directed to the ticket office. The member of staff at the door took us to a ticket machine – old tickets in – choose train and seats on new train and out come old tickets and new tickets – all done no fuss, no bother and no charge.
On to the platform and off we go…