In Japan for 18 days in August

Hi Daniel-san.

We are a group of 8 adults traveling in Japan for 18 days as follows:

Haneda airport to Shibuya/Tokyo
While in Shibuya - trips to Mt. Fuji, Tokyo Disneyland

Tokyo to Hiroshima
Day trip to Miyajima

Hiroshima to Osaka
Day trips to Kobe and Nara

Osaka to Kyoto
Day trip to Nagoya

Kyoto to Haneda airport

Will it be more cost effective to buy the JRPass?

Thank you!
Sharon/MeHere