Their performance was smooth, innocent and sweet, with a hint of flirtatiousness.
But the path leading to the launch of K-pop quartet SKarf - which made its official debut in Seoul on Tuesday - was anything but smooth for the two Singapore girls in the group.
Everything was controlled - from what they could and could not eat to what they could and could not do, both in public and in private.
The girls also suffered culture shock, like having to walk around completely nude in a public bathhouse.
Ferlyn Wong, 20, one of the two Singaporeans in the group (the other two are Koreans), told The New Paper that she took more than half a year to get used to her new life.
She said: "In the past, in Singapore, I went where I wanted and ate what I wanted.
"At the beginning (of my training in Korea), I thought to myself, why is (the company) controlling my life? I didn't sell my life to them.
"But I realised later it is for my own good, so that I become a better person and my weight doesn't go up."
The other Singaporean is Natasha Low, 18, the leader of the group.
The two girls, who beat 3,000 starry-eyed hopefuls in an audition two years ago, signed with Singaporean-owned company Alpha Entertainment and moved to Seoul about a year ago to train to be part of a K-pop girl group.
Both now go by their stage names Ferlyn and Tasha.
They are joined by Koreans Jeong Sol, 21, and Lee Joo Young, 16, or Sol and Jenny respectively.
The New Paper was at SKarf's showcase at Ilchi Art Hall on Tuesday afternoon, where they performed their songs My Love and Oh! Dance to around 70 Korean reporters, one from Hong Kong and four from Australia.
The digital version of their songs will be released in Korea on thursday and the CD single will be on sale in Korea next week.
The release date and pricing for Singapore has not been confirmed.
SKarf will embark on a month-long promotional tour around Korea and will be coming to Singapore for an event as early as this month.
In an interview late at night, after their performance, Ferlyn revealed that the girls live a strict life.
They are not allowed to eat meat, rice and bread, and they get chicken breast meat only on some occasions.
Their laptops, MP3 players and mobile phones were also confiscated on separate occasions because they had misused the items - they had used them to watch videos and text message late into the night when they were supposed to be resting. The electronics are to be used only for training purposes.
Ferlyn said she was especially affected when her phone was taken away.
"I cried a lot for a few days. I used to think my phone was my life. It was my connection to my family," she said.
"I even treated the rest of the girls a bit rudely then, telling them not to talk to me.
"I didn't understand why the company took my phone since I only used it at the end of the day after our training.
"Later, I understood it was because they wanted us to sleep more instead of using the time to message. And I realised (not having the phone) didn't affect my life much."
On an average day, the girls wake up at 6.30am and are at the agency's office at 8am to exercise and learn the Korean language.
After that, it's seven hours of practising their singing and dancing on their own.
They return home at around 1am, after which they prepare their meals for the next day and do some light household chores.
They sleep around four hours a day.
In the four days before their debut on Tuesday, the girls trained even harder and longer, and slept only three hours a day.
Other than their strict regimen, both Singapore girls also had to rapidly adjust to the foreign culture.
Said Ferlyn: "We were like newborns placed in this country to learn their language and culture, and we gave our director a headache.
"Because of our cultural differences, we were portrayed as rude, with no manners.
"For example, the Koreans bow to each other as a form of greeting and when someone enters a room. We didn't do that initially."
Bowing to other people has become so ingrained in Tasha now that she did it unconsciously when she was back in Singapore for a break.
Before their debut, the girls returned home once every three months. Tasha's last visit was last week.
The girls encountered another culture shock when they went to a jjimjilbang (a Korean gender-segregated public bathhouse) with Sol, Jenny and their director Miss Carrie Hwang, 33.
Lead singer Sol, who majored in music in university, said: "Once we were inside, Ferlyn was gobsmacked at how all the women there walked around nude.
"She and Tasha were shy and took towels to cover themselves."
Miss Hwang, who plans the girls' career and takes care of them in Korea, said it was about 30 minutes before the pair shed their inhibitions.
Despite the difficulties, Tasha said she is very honoured to represent Singapore in the highly competitive and popular Korean pop music industry.
"This is a great start for Singaporeans to break into other music industries overseas," she added.
When the group's teaser trailers were released on YouTube last week, Ferlyn went online to see what people saying about SKarf.
"There was so much anticipation from them and that was pressurising," she said.
"Some netizens left positive comments on how proud they are of us... Others said we looked very plain and that we had plastic surgery done on our eyes and nose because we look different now."
Both Singapore girls denied going under the knife. Instead, they credited the difference to exercise, which they said had turned their fat into muscles.
Equally proud of their achievements are Tasha's mother and Ferlyn's mother and older brother, who flew to Korea to see their debut.
Ferlyn's brother Wong Honsonn, a 23-year-old student, said: "I can't believe it's my little sister up there. We have never dreamed of her being a singer."
Tasha's mother, Madam Lucy Wang, 46, a ballroom dance instructor, added: "My tears flowed the minute the girls came out (on stage to perform).
"I turned my head away because I was worried Tasha would be affected if she saw me cry...
"I'm already prepared that she wouldn't be able to come home so often now that she has to travel to perform and promote the group.
"I will be happy enough to see her on TV and in the videos online."
"Once we were inside, Ferlyn was gobsmacked at how all the women there walked around nude. She and Tasha were shy and took towels to cover themselves."
- Korean Sol on the culture shock Singapore girls Ferlyn and Tasha got when they visited a Korean public bathhouse
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