How realistic are ninja stars/ shurikens? Did they ever seen any actual use, or are they the stuff of fantasy and stories? What are their history?

by CrudeImitation
saddetective87

For use as a killing tool like a throwing knife, not so much. For something more like a concealed blade in your fist similar to bladed brass knuckles and used to cause pain/distractions aimed at the openings at the joints in armour so that an operative could escape, much more likely