Sparring is important in the Martial Arts , Sensei Arie van den Akker the inventor of ISF training concepts and Ninjitsu Modern Style at ZVCNoord, and the leader of the 黒竜忍術 Kuroi ryu Ninjutsu School in the Netherlands is fighting against his Fellow student Reinhard a Student of Sensei Andreas Leffler from Germany.founder of the Black Dragon Society Germany ev and student of grandmastetr Ashida Kim. Check this sparring between the two Ninja students. They fight with the traditional Kuroi Ryu Ninjutsu concepts