Ada Wong (Resident Evil 4)

Six years ago, during the Raccoon City T-Virus outbreak, Leon met a beautiful Asian woman, who went by the name of Ada Wong. His first day on the job, the naive rookie cop believed the lady in red about being in search of her lost boyfriend, a scientist called John. In reality, however, the woman was a spy, sent by an unknown organisation. Her mission: to acquire a sample of the G-Virus, a creation of William Birkin's, one of Umbrella's top researchers.

Having supposedly died during her Raccoon City assignment, she crosses Leon's path once again during his search for the President's daughter. How did she survive? Why is she here? The woman named Ada is a real mystery.