Day trips from Tokyo on the Shinkansen

Hi there, I'm going to Tokyo in June with my dad and his one wish from the trip is to ride the Shinkansen. We already have every night booked in a hotel in Tokyo so a day trip is the most ideal. I'm looking for somewhere with a short journey time (maybe 1-2 hours?) that won't be incredibly overwhelming to be at for a day like I heard Kyoto or Osaka would be. We're staying in Asakusa so maybe something a little different. I really like the idea of somewhere more cosy and rural than Tokyo.

by fruit_b0wl