What would be the most cost effective rail pass to buy?

Hi we are planning on travelling to Japan for 18 days arriving in Tokyo on 25/03/2019 and departing Tokyo on 11/04/2019 evening. Tokyo (3 nights)with a day trip to Mt Fuji - Osaka(2 nights) - Takamatsu (1night) - Hiroshima (2 nights) with a day trip by ferry to Miyajima Island - Kyoto (4 nights)with a day trip to Nara - Takayama (1 night) - Kanazawa (2 nights) - Matasumoto (1 night)Tokyo(1 night) . We would like to take the bullet train from Tokyo to Osaka. What rail pass would you recommend for our trip and how much would it cost ? ($AUD) Thanks.