I bought the BLACK M size. I usually wear size M, 23.5cm, and it fit my feet perfectly. The heel height is just right, and the sole is black, so it really brings out the overall color.

The actual color was a little more rose-like than in the photo, but the enamel was shiny and cute, so it might be easier to match with your existing clothes than the bright red. I usually wear shoes that are 23 or 23.5, so I chose the M size, but it was just right if I was barefoot or with thin lace socks. If you want to wear normal socks, you might want to choose a slightly larger size. I liked them, so it was all good in the end, but I felt that the color was different from the photo, so I chose a 4.