Why can't Yuzuru Hanyu perform outside of Japan?

Ok, I'm not familiar with figure skating competitions, but I do like watching videos of famous routines. It is a gorgeous sport. But while watching I of course ran into Yuzuru Hanyu, and he is magnificent on the ice, so I naturally fell into a rabbit hole. In the course of my new found interest I have heard a few times that Yuzuru can't do shows outside of Japan; and I just wanted to know why. Is it true? And if it is, who decides that? doesn't the fact that he is a professional now mean that he is free to do what he wants with his craft? I have researched, but have found nothing, so maybe someone here knows. Thank you.