There was this anime that I watched with this young boy in it and he has this pink haired girl inside of him. When the boy was in danger and needed to fight, the girl would take over his body so that she could do the fighting for him. She switches with him in the same way how the Pharaoh switches with Yugi when it's time to duel, yes she takes over the boy's body in the same way.
I was born in 1990 and I watched this anime when I was a kid, so this anime is old
Can anyone help me?