Kuzaka the Wise was one of the Seven Philosophers who oversaw the construction of Shinjuku Babel in the wake of the Great Cataclysm. A biologist, he created the Innocents to replace the people lost in the Cataclysm in order to help rebuild and revive Tokyo to its former state. As Setsu and Azura were the third and fourth Innocents created by him, they feel a special attachment to him and refer to him as their father. However, in order to fulfill his brother's dying wish, Setsu breaks the single rule that Kuzaka established regarding the Innocents by giving them weapons.