Matsumura Bassai is said to be the original form that Matsumura Sokon used to practice, it was passed on via Matsumura Seito as well as via Tawada (who himself passed it to Choshin Chibana) In Chibana’s Shorin-ryu, this is what they call Passai Dai (and the more famous Itosu Passai, also known as Bassai Dai in Japanese styles, is relegated to Passai Sho there) It found its way to Shito-ryu later on, when kata from other styles were being added to it
