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.
