Ninja nationalities no joke

Kai and Nya Japanese Kai is a Japanese name meaning worthy and in some Asian cultures it is linked to fire while the name Nya in Japanese culture symbolizes the sound of a cat as for their family profession it is blacksmithing and Japan was famous centuries ago for making swords and warrior armor also Samurai X is inspired by ancient Japanese warriors the Samurai and this is a purely Japanese symbol Jay British why not American because I am presenting the original ethnicity of the characters...