Etymology and distribution of 辨納.

Ben'nou 【辨納】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Oosaka-fu , Kagoshima-ken , Hyougo-ken . Creation . "Yuan" was added to Yu who is the surname of Amagi archipelago of Kagoshima-ken . Estimated at the time of returning to Japan in 1953. 勇 Isami reference.