I'll probably never have the time or money to take this trip, but it would be a dream come true. Highlights of Japan, everything from urban centers to temples to historic villages, all during cherry blossom season.
I think its a possible trip. Make sure you have a rail pass to travel with. YOu will save hundreds if not thousands of dollars this way. Traveling across Japan is so expensive. Buy your airline ticket through a travel agency specializing in Japanese travel. To save money you can go through youth hostels as wel..I would add Miyajima to your trip and Okayama Caves since you want to see Hiroshima.