This isn't popular enough, so I'm gonna do it my own way.

In the fifth season of Hetalia, which is The Beautiful World, in Episode 15, a girl's point of view was picturing France until he comes towards her. The girl's name is Lisa, if you don't know.

As many Hetalians know, France believes that she is the reincarnation of Jeanne d'Arc, the person he loved years ago, but died in May 30, 1431.

I personally think that Lisa has amnesia, and can't remember her past. Nothing at all.
When she met France and knew his name, a nostalgic feeling rushed through her, meaning that she had a flashback, calling his name while she was burned slowly.

I imagine that when Lisa came back to visit France, France was at Jeanne's grave, which means it's May 30, her death anniversary. They went to a bar, as a supposed date. France orders two red wines.

When Lisa tasted the wine, according to her point of view, tastes very familiar. It suddenly rained, so France offered Lisa to stay at his house.

While taking pictures at France's paintings, the third picture has a girl painted with a armor and a flag, looking similar to Lisa, which is Jeanne.

While France finds some towels, Lisa stumbled at his room. Behind her was a piano. She sat down at played a song(probably Eine Kleine by Kenshi Yonezu).

When she's done, she was startled by France's voice. He complimented her being very good at piano. Lisa admitted that she doesn't know that she can play the piano.

At their dreams, Jeanne appears at France's dream, saying that she is Lisa, shocking France. Jeanne smiled and explained what happened. Here's a direct quote of what she said:
"When I was about to die, I heard God's voice and said, 'Jeanne, You will live here in Heaven in a minute. But when you get here, You will live in a thousand years. When your thousand years are done, You will return to Earth. Sadly, you will have your memories erased. Do you want this to happen?' I nodded, even though some of the people noticed me. I closed my eyes, and in one blink, I was in Heaven."

If France found out that Lisa is Jeanne, he'll probably be crying tears of joy.