I received this as a souvenir from a family trip to Hawaii and haven't used it. It's a BOYS size 10-12, which is equivalent to a Japanese women's M size. I haven't tried it on, but when I hold it up to myself, it seems tight on me (I'm 166cm tall, of average build, and tall). I think a size L would be a better fit for someone with my body type. It would likely fit an average Japanese woman (158cm, 45-50kg) perfectly. I've added pictures. Front: 40cm Length: 65cm *measured from the collar Color: Green Big Pony