The cheapest 2 day trip from Tokyo there is: Nikko

This January I went to Nikko with my right- and left arm: Moe-chan. We bought a 2-day ticket at Asakusa Tobu station which only costs 4000 yen and includes the trip to Nikko and back to Tokyo. It also enables you to use the busses in Nikko for free which is super convenient. Because it’s free, I went to places I will probably not ever go but o well, it’s free.
We had fun, just watch the movie.