What is the point of taking the afternoon ferry to Hiroshima if you are going to turn around the next morning and move to Okayama? There would be little time in Hiroshima if you are going immediately to Okayama and on to Osaka in one day. Seems better to take the train from Matsuyama back over the Inland Sea bridge to Okayama for the part-day there and then on to Osaka.

I have to say that you are really packing a lot in, with a lot of travel in between, with little time to see anything. I didn't realize you were locked in to NRT as your international gateway. Perhaps a complete change of plan would work better. From NRT/Tokyo, you could go to Kanazawa on the new shinkansen to see the third of the "3 Best" Japanese gardens, Kenro-kuen, along with the interesting city of Kanazawa and its castle. Maybe follow that with Nagano, Takeyama and Matsumoto, looping back to Tokyo before your flight home.

The itinerary you have sketched out gives me a headache. I wouldn't try to do it and I do speak functional, basic Japanese.