I stayed only one night in Mount Fuji. The journey from Hiroshima to Mount Fuji simply took too long - it involved a change again at Shin-Osaka station after waiting a long time for the Shinkansen (as I couldn't take the Nozomi services on a JR Pass), another switch at Shin-Yokohama, then two very long rides on the local JR service and railway. All in all, it took me about 8 hours to arrive.
It was a shame that one could not actually hike Mount Fuji during May, as the trails aren't open yet.
But the walk around Lake Kawaguchiko was definitely worth it.

2014-05-27 09.02.56 by
jurastudent, on Flickr

2014-05-27 10.17.42 by
jurastudent, on Flickr

2014-05-27 10.20.45 by
jurastudent, on Flickr

2014-05-27 10.53.35 by
jurastudent, on Flickr

2014-05-27 12.01.12 by
jurastudent, on Flickr
Having seen how long it took to get from Yokohama to Kawaguchiko, I decided to take the bus to Shinjuku, which was a lot faster at just under 70 minutes.