7 DAYS JR PASS

This trip is to explore more in Japan (I've been here 2 times and I only stayed in Tokyo, at that time I used JR wide Pass)
So I'm wondering if is 7 days JR PASS worth for my trip?
- Should I buy 7 days JR PASS? - If yes, should I start the pass in my day 2 to be more worth it?

Here's my itinerary
Day 1: from Yokohama departs Tokyo
Day 2: Been around Tokyo
Day 3: DisneySea / in a night departs to Nagoya
Day 4: Been around Nagoya / head to Osaka
Day 5: Universal Studio
Day 6-7: Been around Osaka
Day 8: Kansai International Airport

Appreciate and welcome to any advice
Thank you so much