|By Sensei Robert Koga Volume 4: This volume includes advanced joint locks and takedowns, more defensive techniques against attackers, and other advanced aikido. Approx. 55 min. Sensei Robert Koga worked the mean streets of Los Angeles, California and became the premiere law-enforcement instructor for the LAPD and countless other agencies in the U.S. and around the world. In this 5 DVD Series, he takes us beyond the theory and into the real world of Practical Aikido to teach techniques that have been tried and proven in real-life situations. This series represents one of the finest and more comprehensive works ever presented on this subject.