Members of South Korean girl group Gfriend rehearse in Seoul December 23, 2014. Thousands of Korean children dream of becoming household names like rapper Psy, whose 2012 “Gangnam Style” video was a global YouTube hit, often putting up with punishing schedules in the hope of one day making it big in the music industry. A recent survey of pre-teens showed that 21 percent of respondents wanted to be K-pop (Korean pop) stars when they grow up, the most popular career choice. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon puts on her makeup as she arrives with her mother to take part in a dance class late at night at DEF Dance Skool in Seoul December 16, 2014. Nine-year-old Kim has no time to throw tantrums. She wakes up at 7:30a.m. for school, followed by hours of voice training, dance lessons and cram school before crashing into bed at midnight. Kim is an aspiring K-pop (Korean pop) star. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon (C) takes part in a dance class at DEF Dance Skool in Seoul November 11, 2014. Nine-year-old Kim has no time to throw tantrums. She wakes up at 7:30a.m. for school, followed by hours of voice training, dance lessons and cram school before crashing into bed at midnight. Kim is an aspiring K-pop (Korean pop) star. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon plays the piano during a lesson in Seoul November 20, 2014. Nine-year-old Kim has no time to throw tantrums. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon attends a private English lesson in Seoul November 20, 2014. Nine-year-old Kim has no time to throw tantrums. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon (2nd R) and Yoo Ga-eul (R) take part in a singing lesson at DEF Dance Skool in Seoul November 15, 2014. Nine-year-old Kim has no time to throw tantrum. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon (centre L) and Yoo Ga-eul look at a smart phone as they take a short break at DEF Dance Skool in Seoul November 7, 2014. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon and Yoo Ga-eul (L) take a selfie at a restaurant in Seoul November 15, 2014. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon and Yoo Ga-eul (L) dance in front of their mothers as they play at a playground in Seoul November 15, 2014. (Photo by Kim Hong-Ji/Reuters)

A video clip shows Kim Si-yoon performing when she was four years old at her house in Seoul December 16, 2014. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon plays a toy guitar at her house in Seoul November 20, 2014. (Photo by Kim Hong-Ji/Reuters)

Kim Si-yoon and her mother pray before dinner at their house in Seoul December 16, 2014. (Photo by Kim Hong-Ji/Reuters)

Jang Ha-jin who was a trainee at S.M, Entertainment, picks out a book at a university library in Daejeon December 18, 2014. Jang made it to S.M. Entertainment's coveted training programme a decade ago after winning a talent contest. She stuck to a seven-day regimen for nearly three years, before giving it all up to return to a more sedate life. (Photo by Kim Hong-Ji/Reuters)

Jang Ha-jin, who was a trainee at S.M. Entertainment, performs in an empty practice room at a university in Daejeon December 18, 2014. (Photo by Kim Hong-Ji/Reuters)

Members from South Korean girl group GFriend receive a makeover as SinB (R 2nd) and Yuju (R) look on at a beauty salon in Seoul December 23, 2014. (Photo by Kim Hong-Ji/Reuters)

Various cosmetics are laid out at a beauty salon in Seoul December 23, 2014. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend rehearse for their debut in Seoul December 23, 2014. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend rehearse in Seoul December 23, 2014. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend watch a recording of their stage performance during a dress rehearsal for The Show in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend perform during a dress rehearsal of The Show in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend perform during “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend perform during “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Fans of South Korean girl group GFriend react as GFriend perform during “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend take a “selfie” after their performance in “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

A member of South Korean girl group GFriend signs her autograph on their album as they rest before “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)

Members of South Korean girl group GFriend leave a studio after “The Show” in Seoul January 20, 2015. (Photo by Kim Hong-Ji/Reuters)