Following World War II, Shimabukuro opened his own dojo, teaching karate out of his home.
One of his early students was an American paratrooper named William Fuller Jr., who arranged for Shimabukuro to teach karate to some of the other American paratroopers stationed in Okinawa.
In 1964 he was awarded a 10th dan red belt, which is the highest rank available within the Okinawan Karate-do United Association.
On October 14, 1969, while in Osaka on his way back from the 1st All Japan Karate Championship, organized by the Zen Nihon Karate-dō Renmei and held at the Nippon Budōkan,[2] where he performed kata Seisan, Zenryo died of appendicitis.
His son Zenpo Shimabukuro became the master of the school his father had founded, Seibukan.