Not removable, but He still looks pretty awesome next to other Tales characters.
It's actually a Kotobukiya figure. You could maybe break the cape off but there's a chance you'd damage the rest of the figure, and even if you didn't, that would lower the value of the figure if/when you want to sell it. I also have no idea if like, his shirt collar and stuff under the cape is actually properly sculpted.
EDIT: took me a bit to see it due to bad lighting where I have my figure, but there is a blue shirt collar there. It might be part of the cape piece though and very likely would break off with it.