Is the JP Rail pass better with two city Itinerary

Hi,

I will be in Japan August 25, for seven nights.

Arrive at Narita airport and staying in Tokyo 3 nights.
Traveling to Kyoto on day 4 and staying 3 nights with a day trip to Osaka.
Traveling back to Tokyo and staying 1 night before departing on day 8 from Narita airport.

Was wondering if the JR pass was cheaper than regular trains in my case.

Also, my son just finished a semester of college and I will be meeting up with him. He can't buy a JR pass there. I'm thinking I can just buy it when I buy mine?

Thank you in advance!

Armand