Quote from jahu
[...] female lead multiplies (as in one personality but multiple bodies)?[...]
As I come to think of it, wouldn't "reincarnation" be somewhat similar to that idea? I'm not sure about this, but if so, then Omae ga Sekai wo Kowashitai nara could be worth a look, because ...
Spoiler (mouse over to view)
The female main character and her male counterpart (both vampires) are actually caught up in a time loop and bound to reincarnate again and again, always with the same mistake as trigger event (One kills the other and starts waiting/longing for the comeback). However - The personality is also part of this loop and comes back along with another character, which takes (more or less) the role of the key to remembrance. And, because they get killed, the body is not exactly the same.
"It's like love is a bonus in your life. Even without it, I'm just fine. I don't feel like pointlessly searching for it. You don't have to make yourself unhappy." (Ookami Shoujo to Kuro Ouji)
"Why does it rain?" - "To create drama." (Drops (Andou Yuki))