JR Pass or individual train tickets?

Hi there,
So, I’m going to Japan for 14 days, and thinking to visit:

Narita Airport – Hamamatsucho ̅ (1 night)
Hamamatsucho ̅ – Osaka (2 nights)
Osaka – Kyoto (1 night)
Kyoto – Tokyo (one way)
Tokyo (4 nights)
Tokyo – Kairuzawa (2 nights)
Kairuzawa – Nagoya (2 nights)
Tokyo (2 nights) – Narita Airport

Do I need to buy 14 days JR Pass? Do you mind to give me some advices if the JR Pass is worth for my travel or individual train tickets is better?
Thank you in advance