Although I don't know your store manager or co-workers personally, I transferred back in January and it was a breeze. My manager probably only asked why once (if she ever asked at all, I can't really remember) and I still enjoy going into my old store and saying hey to everyone. If it's true that the store you are looking at transferring to is close then that in itself is a good enough reason. Tbh I think that just having the desire to go to a new store is a good enough reason, in my opinion it helps you understand the company a bit better. I think you're totally fine!
PS all that being said, the grass isnt always greener in the other side. The new store probably has it's fair share of issues as well, they all do.
Good luck!