Luggage from Kyoto to Osaka

My itinerary has me going from Kyoto to Himeji to Hiroshima. I plan on leaving my luggage in Himeji station when I arrive in the morning and collecting it before continuing on to Hiroshima.

Two days later, I plan on checking out of my Hiroshima hotel and going to visit Miyajima for the day. Once finished with Miyajima, I'll be getting the train to Osaka. Again, I figured on leaving my luggage at Hirsoshima station ready for collection that evening.

Since luggage storage appears to be pricey enough, would I be better off under these circumstances just to bring a small bag holding enough clothes, etc for my Hiroshima trip and sending the bulk from Kyoto straight to my hotel in Osaka?

If I'm reading the Yamato site correctly, sending a standard sized rucksack from Kyoto to Osaka looks to cost about 1580 yen which seems to be around the same as the luggage lockers would cost me in Himeji and Hiroshima? Is there any part of this plan that doesn't make sense, anything I've not considered?

(I know I could probably leave my baggage in my Hiroshima hotel and collect it on the way back from Miyajima, but I'm getting the JR train to Miyajimaguchi so it'd be a lot easier to have everything at the station once I'm done)

How long are you staying in Osaka? you could stay in the same hotel in Kyoto--they would keep your big suitcase--and you can easily commute from Kyoto to Osaka. from Kyoto to the Hiroshima area and back you only need a small bag. When I visit the Kansai I usually stay in Kobe all the time and travel from there everyday to Kyoto or Osaka, Nara, Himeji etc. (back home I commute by train--45 minutes one way-- so it is nothing to me and I love Japanese trains)

I'm staying in Osaka for 3 nights (arriving late from Himeji on Day 1, leaving early on Day 4). I did consider the commute from Kyoto idea when I was making my itinerary and am warming to it a little as I go along.

My plans in Osaka are pretty regular, Dontonbori and DenDen one day, the castle and Tempozan the next, nothing too unusual and since I was planning on making Shinosaka my base for those 2 days, tacking on a 15 min train ride at the start and end wouldn't be a major problem. My only reason for moving really was that I've already had 7 nights in my Kyoto hotel, so was looking for a bit of a change really.

And what about my 3 night trip to Hiroshima - are you suggesting that I keep the Kyoto hotel room aswell, or will they be happy to keep my main luggage while I'm away? Is this something they'll happily do? If I'm packing up to go to Hiroshima anyway, I may aswell change hotels.