should we buy the JR Pass?

hi, my friends and i will be in japan for 10 days in may. I'm wondering if purchasing the JR pass will be worth it. Here is our itinerary

Day1- arrive in Narita; explore Tokyo in the afternoon/evening
Day 2- asakusa/ueno
Day 3-explore tokyo
Day 4- Osaka
Day 5- Osaka
Day 6- Osaka
Day 7- Osaka
Day 8-Osaka
Day 9-Tokyo/yokohama
Day 10- Flight going back home from Narita

*specific places to visit aren't final yet though but most likely we will be visiting universal studios and maybe kyoto will be part of our trip as well

please help us decide if we should buy the pass or not. thanks :)