Izaku: Shuro's clone, created to investigate why ES00 was the only one to survive, since Shuro was the original ES. Created 10 years after Shuro's birth, his code name is ES01. He grew in a mechanical womb during approximately five years. Any light or sound would be kept from reaching him in order to avoid the "rise of sentience"; the researchers planned on dissecting him to study his viscera right after taking him out of the mechanical womb. His name originates from the Old Testament; the devout Abraham offered his son Isaac as a sacrifice to God.