BTS star Jin started his mandatory South Korean military duty on Tuesday, the band's first member to enlist since a hiatus announcement this year left fans heartbroken over the K-pop group's future.
The group is considered the country's biggest-ever cultural phenomenon -- selling out stadiums around the world and dominating the charts while bringing in billions and building a global group of fans known as ARMYs.
But all able-bodied men in South Korea must serve at least 18 months in the military, and while there was a years-long debate about whether BTS deserved an exemption, they confirmed in October that all members will enlist.
Jin -- whose full name is Kim Seok-jin -- reported to a boot camp in Yeoncheon Tuesday to begin his five week training, kickstarting 18 months of military service.
Hundreds of media personnel and BTS fans packed an intersection in front of the boot camp's main gate.
The location of Jin's boot camp close to the border with North Korea, with which the South remains technically at war, has sparked local media speculation that he is expected to be deployed to a "frontline unit" after training.
Fans were stunned in June when BTS revealed they were going on hiatus, citing exhaustion and pressure as well as the desire to pursue solo careers.
The group will reunite around 2025, when its seven members have completed their service.