Master Tatsuo Shimabuku was teaching in the courtyard of his home. In the yard, the Master had a water tank to supply hard working students with a refreshing drink between workouts. One day, after a full day of teaching, the Master sat on top of the tank to relax and soon fell asleep and began to dream.
In his dream, he heard a man enter the gate of the courtyard and approach him. When the man confronted Shimabuku, he challenged the master to a fight, but instead of accepting his challenge, Shamabuku waved the man away with his left hand and made a fist over his head with is right hand. (This open left hand and closed right fist is also the salutation before performing each Isshinryu kata.)
Instead of leaving in peace, however, the man encircled the master in flames, and as mysteriously as he appeared, the man disappeared.
Master Shimabuku used the bucket in the tank to pour water over the flames and all the flames were extinguished - so was his dream. The master awoke.
The next day he went to town, entered a great house and there hanging on the wall was a picture of a woman wais deep in water. He asked who that was in the picture. He was told that it was Mizu Gami, the Shinto Water Goddess.
Mizu Gami was in the same stance that he took the night before in his dream against the strange man. Mizu Gami was also in water, like he was on the tank, and she was using water to extinguish flames in the sea, as he used the water to extinguish the flames around his body.
The Isshinryu patch is of oval shape to represent the vertical Isshinryu fist. In the center is the figure of Mizu Gami (water goddess) and at the top are three stars representing Master Shimabuku's three teachers. A red (sometimes orange) circle signifying the flame that surrounded Shimabuku in his dream borders the emblem.
The patch is always worn on your uniform over the heart symbolizing the "One Heart Way".