Looks like a mon or kamon, Japanese crest or family crest. It's familiar but I can't put my finger on where I've seen it.
It is called a "tomoe" (as in tomoe nage, where the body of tori resembles the shape) and is a symbol associated with Hachimon, who is the Shinto god of war. Because the symbol became associated with the god of war it was also associated with the Samurai and is prevalent on the family crests of may Samurai families. Why do you ask? What is the specific interest? Dao
It's very similar to the Shorinji karate symbol (see the pages below), no doubt due to the Japanese element of the art. http://www.zendoryukarate.com/Shorinji_Zendo-ryu.html http://www.shorinjiryukaratedo.org/ http://www.kenkokan-karate.com/en/top.htm
