Kurau Phantom Memory(2004)

Kurau Phantom Memory

In a world of mercenary agents, Kurau is a martial arts master and elite thief—but she has a secret. Her body has been fused with a binary alien life form called the Rynax. Every moment Kurau lives is lived twice, one alien sharing her consciousness, the other still waiting to be born. The truth about Kurau has begun to spread, and now the ultimate agent is the ultimate target.

(Source: Crunchyroll)