In a post-apocalyptic Japan, Kurisu Saotome, aka Iron Girl, is a deadly bounty hunter with an armored suit granting her great power. She's known as Iron Girl but has lost all memory of who she really is or where she comes from. To regain her memories, she continues her lone battle. With the help of new ally Kent, Kurisu faces off against villains like Poison and Sparati, a ruthless leader, in a quest for truth and identity.