NRT to Osaka to Kyoto to Tokyo

Hello!
We're a group of 7 travelling to Japan from March 7th to March 20th.
We will be arriving in NRT airport and plan to head to Osaka for 3 days. In those 3 days we will be heading to Awashi Island to visit Naruto Theme Park on a day trip and Kobe on the way back to Osaka. From Osaka we will be going to Kyoto for 2 nights. From there we will head back to Tokyo.
Would it be best to fly to Osaka or take the JR pass? If so which JR pass would be best? Should we get the National or does the JR West Regional Pass? Does the JR West Regional Pass include travel from Tokyo to Osaka? We will be travelling from Kyoto to Tokyo to meet with other friends in Tokyo who are only visiting Tokyo so will be using the Local train lines there. Is there any savings in using the JR pass?

Thank you for your help!