It is actually a manji, a historical symbol of many eastern cultures associated with strength and courage. The Nazi's took the symbol and turned it into the Swastika. It is also the kanji for the "ban" in Bankai. Just to piggyback off this, the swastika was actually around long before the Nazis used the term, thousands of years ago even. It is actually derived from Sanskrit, and was said to represent good luck. This is the version that the Japanese manji was derived from.