I can't see any romance happening here. The capture targets are out of the question, even if he has a female body, MC is still an old man inside. I don't think he's gay, so a romance would be so weird. And for Anna, she's probably around the age of his daughter, there's no way he would have any romantic feelings for her.
I wonder if the underlying Grace influence of the body will prove stronger or weaker than the Oji-san influence of the memories when it comes to romantic interest.
Still, I do hate when reincarnation isekai keep implying there is one person inside another person. That doesn't even begin to make sense. Is it supposed to be little internal people all the way down like those Russian dolls? https://en.wikipedia.org/wiki/Homunculus_argument