Reincarnation
It was funny, how reincarnation worked.
She looked like Kikyou; she knew she did. Flatten her hair, slap on an 'emotionally-dead' expression, and there it was. They probably could have passed for twins when Kikyou was 15.
But Inuyasha...he'd come back looking almost nothing like himself. There were touches, around the eyes, the shape of his hands, but that was it. No white hair, no fangs, no claws. No dog ears.
But he remembered it all, every day of that wonderful, magical, painful, devastating year. And she was the mirror-image of a dead woman.
Yeah, reincarnation was real funny.