Greg and Robin Brandt will proudly watch their two daughters make their Olympic debuts this weekend at the Gangneung Ice Arena in PyeongChang, South Korea. But with a few surprises in the women’s ice hockey tournament, they might be forced into an unusual predicament: choosing sides.

It’s not often siblings represent different nations in the world of sports. It’s even rarer to see it on the Olympic stage-with the possibility of going head-to-head against each other.

Raised in Vadnais Heights, Minn.-a suburb 10 miles north of St. Paul-. unsurprisingly grew up loving ice, first as a figure skater, then as a hockey player. After leading Hill-Murray High School to its first-ever girls’ state tournament appearance, Hannah went on to become a star forward at the University of Minnesota, where she won three national championships in four years. She couldn’t secure a spot on the United States’ 2014 Sochi squad as a sophomore with the Gophers, but she made the cut for PyeongChang four years later.

Melissa Brandt grew up side by side with Hannah, and has had a very similar journey. She played every sport she could with her sister, from dance to gymnastics to soccer.

“We were best friends,” Hannah said.

In high school, Melissa anchored Hill-Murray’s blue line while Hannah lit the lamp, and she decided to play collegiate hockey for Gustavus Adolphus, a Division III program in St. Peter, Minn. During her senior year, Melissa got a phone call and was offered the chance to try out for a spot in PyeongChang.

But Melissa’s Olympic bow won’t come with Team USA. It will come with the joint Korean team, playing under her birth name: Yoon-Jung Park.

It had been almost 25 years since Melissa had visited her country of birth, where Greg and Robin adopted her from when she was four-and-a-half months old. But Korea’s goalie coach, Rebecca Baker, had strong ties to Minnesota, which tipped her off to Melissa’s ability and heritage. She was on the other end of the phone. Melissa packed her bags for Seoul.

She hadn’t been interested in Korean culture as a child (though, funnily enough, Hannah was), but Melissa grew to appreciate her roots, and is slowly learning the language. She regained her South Korean citizenship in 2016.

“I’m happy I took that leap of faith,” Melissa said.

She settled in quickly. Before long, Melissa was close enough with the rest of the squad that they had a team meal at the Brandts when they traveled to Minnesota for training camp and exhibition games (before merger between the South Korean and North Korean teams). After dinner, there was a dance party in the basement. As the Games approached, Melissa was awarded the “A” as an alternate captain.

“Marissa has been a wonderful addition to our team,” head coach Sarah Murray said. “She is a great player and an even better person.”

The inexperienced Korean roster faces long odds to make it out of pool play, but if it manages to advance, the team could very well find itself matched up against the United States: one of the pre-tournament favorites for the gold medal.

It would mark the first time in more than 15 years that the Brandt sisters take opposing sides on the ice.

“It would be fun to play her in the Olympics,” Marissa said. “Not awkward at all.”

But even if they aren’t used to playing against each other, don’t expect either to take it easy against the other. They are Olympians, after all.

“We’re sisters, but when we’re in the Olympic Games, we’re going to be competitive,” Hannah said with a smile to Yonhap News after a practice session on Wednesday. “It’s my team versus her team at that point.”

As for their parents’ allegiances?

“I think Greg would probably root for Korea because they’re such an underdog,” Robin said. “I’d just cheer for both girls and hope they do well.”

Scott Charles and the Associated Press contributed to this report.