SIJO (system founder) Waysun Johnny Tsai is a Chicago Native and the founder of C.U.M.A. COMBATIVES and the C.U.M.A. SURVIVAL SCHOOL. A master level Instructor, Sijo has over 33 years of combined experience in teaching practical street defense in the civilian, military and law enforcement sectors and is considered one of the world's foremost experts in practical street defense and combatives. He is published book, magazine and DVD author as well as a highly established impact and edged weapons designer. Currently his designs are available through TOPS KNIVES, SLYSTEEL KNIVES, DAY ONE GEAR, COMBAT READY KNIVES and GRUNT STYLE.