Kim Jong Un was meant to be their only idol - then North Koreans discovered K-pop

To play this video you need to enable JavaScript in your browser. This video can not be played Figure caption, Watch: Songs that changed how some North Koreans saw the world By Hyojung Kim BBC Korean , Reporting from Seoul Published 8 minutes ago On a sunny Saturday in June, Lee Yeon-su took the day off from work and hopped on a train from Seoul to Busan for yet another concert by pop supergroup BTS. It was her third time in as many months. She had been in the crowds that poured into central Seoul in March, when the septet launched their comeback - but the stage was too far away. In April, on the first day of their world tour, the rain poured down, drowning out the singers' voices. But this time in Busan, it was "incredible". "Every time I come to a BTS concert, I realise how happy I am that I can like and support someone of my own free will," Yeon-su, which is not her real name, says. "That would have been unimaginable in North Korea." That's where she was born, in the so-called Hermit Kingdom, just north of the heavily fortified border with South Korea. The outside world was out of reach, cut off by a regime built on fear, surveillance and loyalty. "You had to be selected to attend events and if you weren't, you had to stay home with your curtains closed." Now in South Korea, she can decide who to cheer for and how. In Busan, alongside a vast fandom, she screamed, jumped and sang at the top of her lungs, especially for her old favourites, the high-octane Fire and hip-hop hit Mic Drop. Image source, Lee Yeon-su Image caption, Yeon-su revels in joining the crowds cheering for BTS because it's her own choice Growing up in a military family, Yeon-su was taught the South was the enemy. When she escaped, she tried to keep her distance from South Korean culture. But music found its way into her life. She made it out in 2011, before BTS debuted, before K-pop became a global sensation. Now, even listening to it, or watching shows from the South, is a crime in North Korea that can land people in jail or worse. Some like Yeon-su say they had never heard South Korean music until they crossed the border. When they did, it opened up a whole world of freedom and fun, helping them adjust to a strange, new life that was now completely their own. But other defectors tell the BBC that despite the restrictions, K-pop has cut through in Kim Jong Un's stifling dictatorship. They say they used to listen to songs in secret, often not knowing who they were listening to, but clinging to the mysterious and hopeful lyrics. Some even managed to watch K-pop performances, shocked by the blue-haired idols wearing make-up: "Why do men look like that?" "North Korea is a place where the whole system is set up so that there can only be one celebrity, one idol - Kim Jong Un," says Hannah Oh, a 25-year-old defector. But as it turns out, North Koreans have discovered other idols, like BTS and Blackpink, and before them, Girls' Generation, Teen Top and 2PM. BTS's Korean name Bangtan