Director Jonas Poher Rasmussen was a high schooler when he met the person who would come to inspire his latest documentary, “Flee.” But it wasn’t until almost 20 years later that he learned his classmate’s harrowing backstory.

The animated film “Flee” centers on Rasmussen’s longtime friend Amin Nawabi (a pseudonym) and his dangerous journey  as a child to escape his home in Afghanistan to safety in Denmark.

“A very dear friend of mine [Nawabi] arrived in my sleepy Danish hometown when I was 15, and he was 16,” Rasmussen recalled in an interview for Variety Doc Dreams presented by National Geographic. “He arrived all by himself from Afghanistan, but he never told me or anyone else about why and how he had come.”

Rasmussen says he has always been intrigued by Nawabi’s upbringing, but it took time to convince his friend to share a deeply personal story.

“Already, back then, I was curious about how and why he got there, so I think my curiosity was there all along for 25 years now,” Rasmussen said. “I asked him 15 years ago if I could do a radio documentary about him. I have a background in radio, and I asked him to do a radio documentary about his story.”

At that point, Nawabi wasn’t ready to tell all.

“He then said that he didn’t feel ready to share his story yet, but he knew that he would have to at some point, and when he was ready he would share it with me,” Rasmussen said. “Keeping a secret like that is really hard, because you have to keep everyone at a distance because you’re afraid to expose yourself … he just needed to be ready himself.”

Rasmussen opted to animate “Flee” — an unconventional way to craft a documentary — to protect the subject’s true identity. The film has been unanimously well received and looks to find itself in the awards race.

“All the attention the film gets just reaches a broader audience,” the director said. “I’m extremely grateful for that. And also [for] Amin to see a story like his, that people relate to it and feel attached to it, it means a lot to him as well.”

Watch the full video above.