1. Longest running group without any member changes
Brown Eyed Girls is one of the very, very few girl groups that went past 7 years without any member changes, and the only one that managed to reach 10. The girls debuted on March 21st, 2006, and celebrated their 10 year anniversary last year with a 10-year anniversary concert. They haven't been so active as a group lately as members get married, but hopefully, we see them together soon.
2. Youngest idol to debut
Janey was born on December 1998, so when she debuted with GP Basic in April 2010, she was just 11 years old! She's not only the youngest female idol to debut, but the youngest idol to debut period. She amazed with her rapping ability even when she was so young, and has even appeared on 'Unpretty Rapstar'
3. Oldest idol to debut
Kahi was born in 1980, and she was 29 years old when she debuted with After School in 2009. She had actually been active as a dancer for years before that, dancing for many celebrities such as BoA.
4. Shortest time to #1 on mainstream music show
Black Pink debuted with "BOOMBAYAH" and "Whistle" on August 8th, 2016. Not too long after on 'Inkigayo' on August 21st, 2016, the girls took their first ever #1 with "Whistle". The 13 days is the shortest that any girl group had to reach #1 on a mainstream music show.
5. Longest time to #1 on mainstream music show
Jewelry debuted in 2001, and it took them over 4 years to win with "Super Star" on May 1st, 2005. The total record is 1494 days, way longer than it took any other girl group to reach the coveted #1 on a music show. Even counting 'M! Countdown', the girls won their first #1 on April 28th, 2005, just 3 days ahead of their first mainstream music show win, so they still hold the record.
6. Most-watched debut MV on YouTube
At almost 205 million views, Black Pink's "BOOMBAYAH" is not only the most-watched debut MV of all time in K-pop (beating NU'EST's 66 million), it's also one of K-pop most watched MVs on YouTube. All of Black Pink's MVs have a lot of views, so it's not surprising that their debut MV is the most watched.
7. Most-watched MV of all time on YouTube
At almost 250 million views, TWICE's "TT" is the most-watched MV on YouTube for female idols. "TT" also broke various records when it came out, such as reaching millions of views the fastest. TWICE's MVs are always a treat to watch, so check it out again above.
8. Longest #1 on Melon's real-time chart without dropping
TWICE's "Cheer Up" stayed #1 on Melon's real-time chart for 562 hours straight (over 23 days), the longest not just for female idols and idols in general, but for all singers. It's a record that most likely won't be broken for a long, long time, if ever.
9. Most non-Korean members
TWICE has 1 Taiwanese member (Tzuyu) and 3 Japanese members (Mina, Sana, Momo), making TWICE the groups with the most non-Korean members. As 4 out of 9 members are not Korean, they're actually almost half non-Korean.
10. Shortest idol
While not really active as an idol anymore, Tiny-G's Dohee (and her group named for their height) is the shortest female idol at 150 cm (4'11"). Out of the girls who are still promoting as idols, f(x)'s Luna is rumored to be 151 cm. Just going by profile height, Brown Eyed Girls' Narsha is 158 cm.
11. Tallest idol
UEE is also no longer active as an idol, but at 173 cm / 5'8" (there are rumors that she might actually be taller), UEE is the tallest female idol to have debuted. As for idols who are still active, G-Friend's Sowon is 172 cm.
12. Shortest trainee period
No one can beat former Wonder Girls' Yenny for trainee period, as she had 0. She was cast into Wonder Girls directly after auditioning through MTV Wonder Girls Season 1. Looks like Yenny is just born with musical talent, as she was one of the main vocalists for Wonder Girls and is now active as singer-songwriter HA:TFELT.
13. Longest trainee period
PRISTIN's Xiyeon is one of the youngest members (second youngest), but she's been with Pledis Entertainment for so long that she has the longest trainee period of all idols. She's been a trainee for a whopping 9 years, and fans can spot Xiyeon in various Pledis artists' MVs. She's in After School's "Bang" as well as Orange Caramel's "Magic Girl".
14. Most followed on SNS
Taeyeon has 10.2 million followers on Instagram, more than any other female idol on any SNS platform. She's actually one of the most followed idols including all boys and girls.
15. Highest ranking on Billboard 200
2NE1 is the highest-ranking female idol on Billboard's main chart, Billboard 200. They landed at #61 with their 2nd (and sadly final) full album 'Crush', with the title song "Come Back Home".
16. Most number of first-week album sales
Has anyone noticed how many times TWICE is on this list? Truly the nation's girl group, TWICE also holds the biggest record for the most first-week album sales with 'Signal'. 'Signal' sold over 114k albums in the first week. Even more impressive, TWICE also holds the #2 and #3 records - 113k+ sold of 'TWICEcoaster : LANE 2', and 94k+ sold of 'TWICEcoaster : LANE 1'.