I just want to let people know our most recent experience, since I found nothing on this forum actually helped to ease our minds about the luggage situation in Himeji before our trip. The only other thread found was not helpful to me at all.
We were at Himeji on April 7th as a stop over from Hiroshima to Kyoto. We arrived in Himeji just before 9:00am and found plenty of lockers in various sizes available at the station. We had 2 carry on clothed bags sized: 20"L x 9"W x 13"H. and used one medium sized locker for both at ¥400.
There was no lines when we finally arrived at the ticket window around 9:15am. We received our "paper" that validated our entrance into interior paid for the combo tickets and walked right in.
We noticed more lockers in various sizes near by. Yes this includes large sized lockers also. Himeji has the most amazing exterior and gardens around but disappointing empty interior that perhaps will only excite an architect who enjoys looking at wooden structures without nails (IMO).
After we saw everything within the castle grounds while exited around 10:45am, there were so many people and tour groups by this time. But most of the lockers were still unused. We then went to Kokoen Garden, and behold there were even more lockers in various sizes there. We exited the garden around 11:30am and again most of the lockers were unused.
We got back to our locker at the station ready to leave around 12:30pm, there were still some lockers available through out the station but all of the lockers by the Shinkansen entrance (where we stored ours) were occupied.
Hopefully this report will help those who doesn't want to use the shipping service in the future. We were there during full bloom of the cherry blossom season.Edited: 22 April 2015, 07:09