Nikko is one of the popular destinations from Tokyo. You can visit there as day trip. Of course if you stay there, you can visit many places in outside of Nikko city and also can enjoy hot springs in Kinugawa Onsen too.
I have written about access to Nikko by JR Pass before. At that time, I did not expect travellers who want to use other than JR Pass. But since I opened this website, I found many of you are looking for other ways or deals other than JR Pass
These trains connect Shinjuku and Ikebukuro in Tokyo, and Nikko and Kinugawa-Onsen. These trains run on JR line and Tobu Railway line. That means you have to pay extra if you use JR Pass. JR Pass cover JR line portion only. But if you use JR East Passes, such as JR East Pass Nagano Niigata, Tokyo Wide Pass, JR East Pass Tohoku, both JR line and Tobu Railway lines are covered. This may be complicated for you.