You don't need a JR rail pass to cover your days in Tokyo, unless you have money to throw around ( or you have multiple long-distance day trips, spending more than 17200 on train for the additional 7 days).

Typical itinerary is to use the 7-day pass to cover Tokyo-Osaka-Hiroshima-wherever-Tokyo.

Meanwhile,

Tokyo JR day pass 730
Kamakura-Enoshima day pass 680 (from outskirt of Tokyo)