Travelling for two weeks from Osaka to Kyoto and then to Hiroshima and then back to Osaka in early July

Hello there
My wife and I are will be arriving in Osaka in early July and would like to to stay they first 4 days in Kyoto and Osaka and then travel to Hiroshima by train and stay there three days. However we would also like to see some of the smaller towns and cities between Kyoto and Hiroshima. My question is this. "What is the best Japanese Railway pass to use if we are hoping to stay a couple of days in two more places between Kyoto and Hiroshima and continue with train to Hiroshima and then fast train back to Osaka?". My second question is this' "What are some lovely smally towns close to the coast to stay in between Kyoto and Hiroshima?" I look forward to some helpful replies.