Hiroshima and Himeji Castle are absolute musts for us. Miyajima we could miss if time prevents (though I expect we will not have to miss it). It will be a full-on day but the following day, after Himeji, we can rest on the train and, as we are staying at the Tokyo Station Hotel, there is no major transfer hassle.

I am disappointed that Kozantei Ubuya in Fujikawaguchiko is unavailable. But it seems to be unavailable for all dates so I wonder if they have not opened up bookings yet? Konansou may be my second choice.