Yes in verious sizes.
The supply of lockers in the JR station is limited; however, there are many other options. First, be aware that lockers are at two or more locations within the JR train station. If you have exhausted these possibilities, exit the JR train station toward Himeji Castle and take the sidewalk to your left. There is an additional set of lockers in a room several tens of meters in that direction. If you still haven't found a vacant locker, cross the street in the direction of Himeji castle and inquire at the nearby bus station; they have many lockers and if these are all full or too small then they may even be willing to manually check your luggage behind their counter in exchange for a modest fee. If that doesn't work, there are many lockers at the nearby Sanyo Himeji train station, which is completely separate from the JR train station. Finally, there are a few lockers at the Himeji Castle site itself; however, if you haven't yet found any vacant ones, then chances are slim that you'll find any at Himeji Castle.
I know all of this because I had the misfortune to travel to Himeji via shinkansen with a party of 9 all with rolling luggage, on a very busy holiday travel weekend. This may well be a worst case scenario. We eventually found places to stash our luggage. The people at the JR station and the Himeji tourist information center know less about lockers than you do, now that you have read this message.
Yes they have but they can be quite costly. I've used the one outside Sanyo Himeji station (about 2mins away) and they come in various sizes - you will be able to fit both backpacks and luggages. Be sure to keep your receipt carefully after you get a locker as you will need it afterwards. I had to empty my bag my entire bag the last time looking for it!
There are a lot of lockers in the redesigned station, both in the JR side as well as in Sanyo Station. There are lockers at the castle as well, though not as many. There are also smaller lockers available in the larger stores between the station and castle.
Unfortunately there aren't any great online maps of the lockers; you'll see some before you leave the gate. For the others it's probably best to ask a station attendant.
At the time when I checked luggage at the bus station counter, the price was somewhat higher than the price of a coin locker at the train station. I still thought that it was quite reasonable, at a time when I couldn't find a locker elsewhere.
We were there last year during the busy weekend of the Sakura season when it seems half the world was at Himeji. We could not find lockers near the exit of the Shinkansen. But when we walked further away from the exit, we found some available lockers. There are many lockers at the station but they are located in many different corners.
Thank you OP and the posters for the information.
thank you very much for your post- very helpful information
I'm sitting in the station now and want to add more precise info.
1) there is a small group of lockers behind the escalator for platform 11 (shinkansen). The big lockers (8) go fast.
2) there is a very small set of lockers one floor down, on the concourse between the Central and East exits.
3) there is a large group of lockers near the southern side of the station. Take the Central ticket exit, then turn left towards the southern building exit, then turn left after the exit and very soon you'll find some lockers on the side of the building and then a room of lockers.
4) the lockers mentioned by a previous contributor on the northern (castle) north of the building, plus the ones further away at the castle and Koen-ko.
5) there are some lockers (I only saw the sign) in the Grand Plaza (?) Underground shopping centre, just north of the station.
I think many people travelling with large cases in Japan skills really consider the takkyubin services (parcel/luggage courier) from/to hotel/airport/etc. It's often less than 20,000¥ and reduces stress significantly.Edited: 03 October 2016, 23:24