You can rent a kimono with and without reservation (I made one just in case). The process is actually quite fast and the assistants are really helpful when choosing your kimono and add ons like ornaments;etc that will add some to the total price, BUT you can easily stay on budget and still look great with their Standard package.
It takes about 30 minutes to get ready and then you can pretty much rock a kimono until closing time for the shop ( around 17hrs) overall it's a great value for a super fun experience!