They are the only K-pop girl group without any Korean members.

And now Blackswan has made its debut in South Korea. As the genre continues to globalise, the girl group has become part of a growing conversation about the definition of K-pop - and whether they fall within it.

It is not unusual for K-pop groups to have foreign members, typically from other Asian countries. One of K-pop's biggest girl group, Blackpink, has a member from Thailand. The band, Blackswan, consists of Sriya, who hails from India, Fatou, who grew up in Senegal and Belgium, Gabi, who is Brazilian-German and NVee, who hails from the USA.

"They are affiliated with a Korean entertainment company, debuted in South Korea, and sing in Korean," said one commenter, suggesting they should be defined as K-pop. Other Koreans, however, are less positive. "Without them actually being Korean, they are just a pop group."

Blackswan are unfazed by such comments, saying that they identify as a K-pop group and sing in Korean. It is an argument that will likely continue to divide Korea, as the government plans to launch a two-year "K-culture training visa", enabling foreigners to undergo K-pop training. An increasing number of entertainment companies are now offering trainees and idols more personal time now that some of the rules have been made more lenient.

Blackswan's line-up is seen as reflecting the development of the K-pop, with its members confident that they represent the future of K-pop.