Three years ago, doctors diagnosed Mira Erdmann with a very rare auto-immune disease that affects just one in 1.2 million people. As a result of her condition, Mira was in need of a bone marrow transplant, and only one person in the world was a perfect match.

That man was Chrestean Werth, who got the call informing him that he was Mira's only match just three months after he registered to become a donor. Chrestean's stem cells were harvested in Germany and then sent to Mira's doctors in Cincinnati. Now, the two are finally meeting this week.

"It's so emotional, I can't even describe it. I wish I could come up with words. You just can't," said Mira's mother, Tania Erdmann, to ABC Green Bay affiliate WBAY.

After the transplant, Mira experienced several complications, and was only given a five percent chance of survival. Fortunately, today, Mira is nearly 100 percent healthy.

"He's not one in a million. He's like one in 50 million… or more… or more," said Erdmann.