Nagoya to Hiroshima - day trip

Hi, I'm in Kawashima for work in December, but should be able to get out and about at the weekends. Is it possible to visit Hiroshima and Kyoto for day trips from there, and how would I go about it. I'm finding the train information confusing (note - I get lost easily, but always find my way back and usually see something/someone interesting on the journey!).
Some basic guidance would be useful, just to start me off.
Thanks!
Lydia