Tobu Railway offers 3 passes for travel in Nikko that you can ONLY buy in Asakusa, Tokyo. All Nikko Pass ¥4400 : 4 Days Unlimited>;
The best pass is the “All Nikko Pass” which covers unlimited bus service for 4 days from Tobu/JR Nikko train stations to as far as Yumoto Onsen. Sights along the way include; the world heritage sites, the Akechidaira ropeway, Kegon Falls, Lake Chuzenji, Senjogahara and Lake Yu.
It includes a roundtrip train from Asakusa in Tokyo to Shimo-Imaichi. Shimo-Imaichi station is central Nikko. From Shimo-Imaichi you have unlimited travel for 4 days of train service including going to Kinugawa Onsen in the northern part of Nikko city. (Realize that Nikko is a large city, the 3rd largest in Japan)
When going directly to Tobu Nikko station, be careful, the trains sometimes split at the central Nikko hub, Shimo-Imaichi station, some go west to tourist Nikko (Tobu Nikko station) and some go north, past Kinugawa to Aizu Kogen.
It includes a roundtrip train from Asakusa in Tokyo to Shimo-Imaichi. From there you have unlimited travel on the trains for 2 days between Shimo-Imaichi station (Central Nikko) west and north to Tobu Nikko station and the Kinugawa area in northern Nikko. No bus service included in this pass. This pass has a mix and match pricing scheme depending on which theme parks you want to enter.
If you have no plan to go up the mountain to sites like the ropeway, Kegon Falls, Lake Chuzenji, Senjogahara and Lake Yu and ONLY plan to visit the world heritage area, then go for this basic pass. For some weird reason, it includes the train to the Kinugawa part of Nikko, as well. unlimited 2 days.
The above tickets can only be bought at Asakusa and include round trip train transportation to Nikko and buses in Nikko (specific buses for each)
Below are the tickets that you buy in Nikko only at Tobu Nikko or JR Nikko train stations.
Other tickets and passes :
¥500 World Heritage < > Tobu Nikko station or JR Nikko station
¥2400 Lake Chuzenji < > Tobu Nikko station or JR Nikko station
¥3500 Yumoto Onsen < > Tobu Nikko station or JR Nikko station