|Matsumora was born in Tomari
village, on Okinawa Island. At the age of 15, when
in those days boys began to be treated as adults, he
started to learn karate from Master Teruya of
Tomari. The young Matsumora became one of Master
Teruya's main students, even though he had many
Master Teruya taught Katas which were only practiced in Tomari, namely "Rohai", "Wanshu" and "Wankan" (sometimes known as "Okan"). He also placed a great deal of emphasis on good behaviour, citing "Karate-ni- Sente-Nashi" ("there is no first attack in karate").
In those days, karate was usually practiced in the garden or at the cemetery of the master's family, as it was the most convenient place. One evening, when Master Matsumora and others were practicing at Master Teruya's family cemetery he noticed an outcast watching his moves intently. Master Matsumora approached him. The man apologised for disturbing Matsumora's training and commended him on his level of skills. He handed Matsumora a piece of paper but, before Matsumora could finish reading the inscription, the recluse had disappeared. Matsumora showed the note to Master Teruya, to which he responded "exactly!". Some time later, Kosaku Matsumora had a flash of inspiration and, in a moment, understood the deeper meaning of the message;
Master Matsumora had several students including Master Choki Motobu, who became renowned for his great fighting skill. Choki Motobu was reputed to have learned only Naifanchi Kata from Master Matsumora, but this is not true, although he did like the kata and so perhaps practiced it more than others. This Kata has been handed down and practiced in Wado-Ryu because Hironori Ohtsuka, the founder, learned it from Choki Motobu.