This cosplay is perfect. I'm 1,70m or 5,5 and I'm wearing a size S. I weigh 55 kilos. I would say that you can easily fit into an S with more or less weight, because the pants have a very elastic waistband. The top was a little less elastic than the pants but for me it was almost a bit too big in width, but the sleeves shouldn't have been shorter. The top is also sewn from a very thick fabric. Also the cosplay included: kimono, top, pants, a high-quality belt (feels like leather), the "socks" with small bows on the back and golden and silver buttons for the top. The kimono has a beautiful pattern that shimmers gold in the light. The pants are super comfortable to wear and are not as warm as some other polyester cosplays. The holes in the belt were not enough for my figure, I had to stab smaller ones. The kimono is just the right length and is nice and easy to wear and does not warm so much. The inside of the kimono is white. The seams are all sewn very high quality and there are no threads. I would recommend this cosplay to every demon slayer fan as it is simply very good in terms of price / performance.
Have a good day:)