JP regional pass vs JP full pass

Hi, I am not sure if I should purchase a 21 day JR pass or do separate regional passes. My itinerary is as follows:

October 22-25 - Tokyo
October 25 - 28 - Kanazawa
October 28 - 31 - Hiroshima
October 31 - November 6 - Kyoto (with side trips to Osaka)
November 6 - 9 Hakone (Odawara)
November 9 - 10 - back to Tokyo for one night before flying home

Your assistance is greatly appreciated.

Kirsty