The historic heart of South Korea's capital is bracing itself for what may well be the year's biggest event: the return of the world's most successful band in recent years, BTS.

More than 250,000 people are expected to turn up on Saturday at Gwanghwamun Square, where the seven K-pop stars - RM, Jin, Suga, J-Hope, Jimin, V and Jung Kook - will perform together for the first time since October 2022.

Most of them will watch the giant screens outside because only about 22,000 people who managed to get the free tickets will enter the concert venue, a smaller area that has been cordoned off.

Ami Ostrovskaia, who moved to Seoul from Russia last year to study, is one of the lucky ones. "BTS is the reason I'm here," she says. "It's why I started learning about Korean history, culture, food, sports, and the language."

Set against the backdrop of a 14th Century gateway to the royal palace, the band's one-hour set will include songs from their long-awaited new album, Arirang, which is set to release on Friday afternoon. Millions around the world can watch the show on Netflix, which has struck a live-stream deal with BTS.