On Saturday 12 November 2016, Katja Orschmann entered the dressing room after a match with her second-division club Union Berlin and picked up her phone. It was flashing to let her know she had missed a call from none other than Germany U-20 team manager Renate Lingor. The former world champion was calling to invite the 18-year-old on the biggest adventure of her life so far – to Papua New Guinea.

"When I saw her name on the screen, I guessed that might be why she was calling," Orschmann told FIFA.comduring an interview at the team hotel in Port Moresby. Less than 48 hours later she stepped out of a plane on the other side of the world to replace the injured Rieke Dieckmann at the FIFA U-20 Women’s World Cup 2016. "I like being spontaneous, so this was the perfect situation for me."

Twin sister Dina, who was already at the tournament with Germany, was particularly delighted by the news and could hardly wait for Katja’s arrival. "She called me up and played a bit of a joke on me, telling me she missed me and would love to come out here," explained Dina with a grin in her first-ever interview with her sister. "Of course, we were thrilled to be reunited again."

The twins’ joy reached unprecedented levels during their 2-0 win in the final group match against Korea Republic on Monday, when Dina struck in remarkable style to give Germany a 1-0 lead before racing to the bench to give her sister an excited hug. "The emotion just bubbled over,” the goalscorer said. “I was over the moon at that moment and thought of my entire family cheering us on at home. In a way, I hugged Katja as if she were a representative for everyone back in Germany. It’s such a wonderful gift that she’s here with me and we can experience this together."

A perfect day for the Orschmanns Katja had her own reason to celebrate ten minutes before the final whistle, when she made her first World Cup appearance as a substitute. "It’s hard to imagine a more perfect day for the Orschmanns," the sisters concluded happily. Although they do not share a room in Papua New Guinea, they spend the rest of their time stuck together like glue.

The pair have been kicking a ball around together since their schooldays and played on boys’ teams until U-13 level before moving to Union Berlin. Buoyed by considerable support from the German Football Association (DFB), the club has since risen to the Bundesliga second division. "We’re able to give it our all individually on the pitch while at the same time looking out for each other,” they added. “In that respect we’re just like any other team-mates."

Though the duo rarely squabble, they explain that Dina has the tendency to be a little too competitive while Katja can occasionally take her neatness too far. But who is the better footballer? "It’s tough to say," said Katja diplomatically. "Dina has come on leaps and bounds over the past few years, both technically and personally." While the defender believes she might have been able to block her midfielder sister’s wonderful goal against Korea Republic, she admits that “it was so fantastic that you wouldn’t want to be the one to stop it".

With only the length of their hair making it possible to tell them apart, the twins now have their sights set on a quarter-final against their European neighbours. "I’ve got great memories of France because I scored my first international goal against them for the U-17s," explained Dina. "It’ll certainly be a step up in difficulty from the group matches – but we’ll be ready for it."

Should they manage to make it all the way to the final, it may be time for another family reunion. "We have two older sisters who are 21 and 24, and one of them is currently in New Zealand,” Dina said. “Unfortunately she hasn’t yet managed to make it here to see us, but she’s got to come if we get to the final.”