If you have a full week in Japan, I'd suggest a run down to Kyoto for a couple of days. If that is your only train travel during the week, a Japan Rail Pass would not make much economic sense. Just purchase [I]shinkansen[I] tickets on the Nozomi and zip down in under 3 hours. I do NOT recommend "doing" Kyoto as a day trip from Tokyo. There is just too much to see for a stay of only a few hours.