We had good day trip to Tokyo. It is around 30 min on the train. It's famous for Bonsai. It's a very easy day trip. Omiya is nothing special - a big city connected to Tokyo. However the bonsai village is pretty, with about a dozen bonsai growers / nurseries within walking distance of each other. If you go, I'd suggest taking a cab from the station to the bonsai village. Once in the village, there are street maps pointing out where the various bonsai places.