As soon as you get out of customs and immigration you will head towards the outside doors. Right before you go outside you can get tickets at the counter you will see a sign for it. You can also hit the Atm up and money exchange booth. I just did this on November 2nd from NRT
You can purchase the bus ticket at the Sunroute Plaza front counter. The bus stop is outside the hotel.
Thank you. Just wanted confirmation that ticket can be purchased from hotel instead of airport.Edited: 18 November 2017, 08:55