January 15th 1956, Master Tatsuo Shimabuku called a special meeting at his home & dojo in  Chan village, Gushikawa city to announce a new name for his unique style of Okinawan Karate.  Previously, his style had been called as Chan Migwa Te (in the late 40s) and later Su Nu Su (early 50s).  On the occasion of Soguwachiguwa (Okinawan dialect) / Koshogatsu (Japanese), the Little New Year, Master Shimabuku announced the official name of his Karate.  He chose “Isshin Ryu” because “all things begin with one.”

The Soguwachiguwa is a 3 day celebration beginning with the full moon in January.  Okinawans would pay tribute to Toshitokujin, a Shinto Kami of agriculture, seeking good fortune for their crops in the coming year.  When the Gregorian Calendar was adopted, January 15th became the day that Soguwachiguwa was observed, and also the day Master Shimabuku chose to name Isshin Ryu. 

Traditionally, the Coming Of Age Day, Seijin-no-Hi, is also celebrated on January 15th.  It’s the mark of entering adulthood.  You could say that Master Shimabuku’s Karate entered its adulthood at this time and emerged as Isshin Ryu.

How will your Karate grow in the coming year?  Hard work combined with good fortune should yield an excellent crop.

In Japan, the Oshogatsu (The Big New Year) was also changed to match the Gregorian Calendar.  In some regions, like Okinawa, the original Chinese New Year date is still observed.