Iron Claw is the leader of a global criminal empire known simply as "Crime". With a network of wealthy and influential sympathizers and employing an army of faceless, leather-masked thugs and cyborg assassins, Crime seeks to become the most powerful mafia organization in the world. To combat this threat, ISSIS, the International Science Special-Investigation Squad, is formed. ISSIS organizes its forces around the world to battle Crime, including Tokyo, Japan. Tokyo's ISSIS branch commander, Daisuke Kujirai, proposes a radical experiment to aid his forces in Japan. Taking the codename "Joker", he recruits four young test subjects to undergo his cyborg enhancement project. Surgically altered and given various energy manipulation powers and bionic enhancements, the four youths begin their mission to destroy Crime as the crime-busting quartet code-named J.A.K.Q. Dengekitai.