JRPass

Should I buy a JPR?

Hello,

We are going to travel through Japan, during 3 weeks.
We are starting in Tokyo, then travel to Nagoya, then to Kyoto, then to Osaka, then to Mount Koya, to Shirahama (in prefecture Wakayama) and finally back to Tokyo.
I don't know if all trajects are covered with the Japan Rail Pass.

Could anyone give answer whether all trajects are included in the Japan Rail Pass?

Thanks,

Monique