Hi Marc, if you get a chance in your trip,i recommand you to stop by Himeji, just to visit the Himeji-sho, said to be the best old Samurai Castle in Japan. You can do that in few hours, it's walking distance from shinkansen Himeji Station (between Okayama and Kobe).
By the way i recommand Kobe too.
Have a wonderful time.
