Sasaki Kojiro was famous for being somewhat vain about his admittedly handsome appearance. Women loved him, and he prided himself on his beautiful hair. In an early encounter, Musashi sliced off Sasaki's topknot. Perhaps this humiliation started their rivalry--they had more than one duel. They're a famous pair of rivals, and an allusion to them represents worthy rivals in Japanese culture.

The character Ukyo Tachibana in Samurai Shodown is loosely based on Sasaki.