BTS star J-Hope started his military service on Tuesday, after posting a farewell message to fans online.
He is the second member of the popular K-pop band to enlist in the military.
In South Korea, able-bodied men between 18 and 35 years-old must enlist in military service for 18-21 months.
Jin was the first to join from the band in December. The rest of the group are expected to enlist in the next few years.
The band announced a hiatus last year to focus on solo projects, with J-Hope recently releasing solo music featuring rapper J Cole.
The 29-year-old posted a picture of his freshly-shaven head on Instagram before being driven to the city of Wonju to take part in the military enlistment ceremony on Tuesday.
The caption said: “I’ll have a good trip!”
The post racked up almost eight million likes from the Army – the name of BTS’s fanbase. Many shared messages of encouragement and support.
The band also posted a final picture all together, with Jin joining in his military uniform.
Many fans turned up to the area of the army base in rented buses covered in pictures of J-Hope to say goodbye to the star.
Questions were raised for years over whether BTS would be forced to undertake the mandatory service, and whether their contribution to the arts should make them exempt.
However, in 2019 the Ministry of Defence rules that they would have to serve.