Kyodai was created for the 1992 animated series, where he was depicted as a Japanese warrior that was trained in Japan by a man named Yoru. When DC brought Kyodai into Rebirth/New 52 continuity they chose not affiliate him with Yoru or confirm Yoru’s existence in that continuity. Instead Kyodai is only depicted as the bodyguard of Kirigi, a man who lives on the border of northeast China and North Korea in present day. Kyodai also doesnt appear to have any conflict or issue with Batman. If he trained with Bruce Wayne under Yoru in Japan it is never revealed.
