Day trip from Osaka to Miyajima

The fastest way is to take the Shinkansen from Shin-Osaka station to Hiroshima station. Then transfer to the JR Sanyo Line to Miyajima-guchi then take the ferry. You can also take the cable car but it takes a much longer time than the JR train. If you want to visit the atomic dome too, you can take the cable car on your way back to Hiroshima station. I advise starting early in order to have enough time.