Matsui Okinaga

Matsui Okinaga (松井 興長, 1582 – July 24, 1661) also known as Nagaoka Sado (長岡 佐渡) was a Japanese samurai who served the Hosokawa clan, during the early Edo period (17th century).

It was Nagaoka Sado himself who had protected Miyamoto Musashi as for him to be able to duel against the famous Sasaki Kojirō in 1612.

Sado had also learned that Musashi had no true intention of entering under the lord's service, and that he was only taking part in that battle (Ogasawara establishment in northern Kyūshū) as a staff in order to be an advisor to his son.

After Sado had then returned to the province of Higo, he began planning the steps to get Musashi into the service of his fief, since he had already known that Lord Hosokawa Tadatoshi was interested in him.

After not receiving a true answer, Sado departed, with Musashi later accepting the Hosokawa offer, as a guest, not a vassal.