Is it possible to visit the Oita Prefecture and Tokyo in the same trip?

I'm trying to plan a trip to Japan for my family. I have always wanted to go. I would really like to see Harmony World in Oita but also really want to go shopping in Tokyo. They seem to be quite far in distance. Is there a train that runs between the two cities? I know I am going to have to do a lot more research and possible hire a travel agent. I was just curious if it was possible to do it all in one trip?