Narita Nikko Airport Bus
The direct bus between Narita Airport and Nikko & area is called the Airport Liner Marronnier.
http://www.chibakotsu.co.jp/en/kousoku/marronnier.html
Haneda Airport & Nikko is the Airport Limousine
https://www.limousinebus.co.jp/en/areas/detail/hnd/utsunomiya
Price is not covered with any regional bus or train pass. Takes about 2 1/2 hours from narita international airport.
Once a day it goes and comes here to Nikko to Narita, most likely you will need to get the bus at JR Utsunomiya (????? ) station, west exit, turn left;
From Narita, the bus will take you to JR Utsunomiya station and here is where you catch the JR Nikko line. Be careful, not every train on the JR Nikko line goes to Nikko; some stop at JR Kanuma!
Bus stand
Airport Bus Ticket office Utsunomiya
Airport Bus Ticket office Utsunomiya
standing in front of the ticket office looking at Utsunomiya station
Airport Bus Ticket office from JR Utsunomiya station
Taking this bus is a great way to save your JR Rail train pass until AFTER spending two or three days in Nikko.
On the flip side, Nikko is a great place to spend you last days in Japan as you can take the bus direct to the airport with less effort than the all the transfers of trains through Tokyo. The ticket office in Utunomiya is on the west side, left when exiting the station.
Nikko is bigger than nearly every travel guide suggests. For example, you will need to buy a separate bus ticket to get to Senjogahara, Kegon Falls, Yumoto Onsen, Mt. Nantai.