This article provides an overview of shoe sizes in Japan, including how they are measured, what factors affect Japanese shoe sizes, differences between men’s and women’s shoes in Japan, and the future of Japanese shoe sizes. It is important to note that the biggest shoe size available in Japan is 30cm which is equivalent to a US men's size 15 or a US women's size 17. Additionally, other factors such as foot width and arch height can also affect the measurements so it pays off doing some research beforehand if you're unsure about what exact measurements you need.