Aoki will play Tatsu Yamashiro - also known as Katana - in flashbacks, reported Ace Showbiz.
The character of Katana was first introduced to DC Comics in July 1983's The Brave and the Bold #200.
Created by writer Mike W Barr and artist Jim Aparo, she is an expert martial artist who trained under a master samurai following a family tragedy.
The first actress to portray Katana in live-action, Aoki is best known for her big-screen work, having appeared in 2003's '2 Fast 2 Furious' and 2005's 'Sin City'.