Any help would be nice.

I am staying at the Marriott - I have been told that it is out of the way. I will be there a week (will have a Japan Rail Pass) and will be traveling with my 2 kids (19 & 15). We want to go to Koyto for one day and to the World Expo for another - the balance of the time would be in Toyko. My kids want to explore the Anime production studios and see as much as they can. Any ideas or tips would be great.

Is the Marriott close to the rail station? Is the rail system easy to use? Can we travel to and from Koyto and the World Expo in one day (leaving very early and returning late?

Thanks in advance for all replies.