Music: f(x)

f(x) in 2010. (L-R) Victoria, Amber, Krystal, Sulli, Luna

f(x) is a South Korean Girl Group formed in 2009 by SM Entertainment. The name is a play on the mathematical notation for function, with "f" signifying "flower" and "x" representing the female's double X chromosome. The group members have also been nicknamed "function girls".

The quartet consists of Victoria, Amber, Luna, and youngest Krystal, who is coincidentally the younger sister of Girls' Generation's Jessica. Member Sulli began her hiatus in mid-2014, and there are rumours she may be leaving the group (these same rumours cite an earlier incident in which Sulli had demanded to leave the group due to being unhappy with the life of an idol, only to be refused).

The group debuted on September 5, 2009 with the release of the single LA ch TA. The lead single off their album Pinocchio gained their first music program win and was their first song to win the triple crown.

As of 2013, f(x) is the first South Korean group to perform at SXSW and they recently did a video with Anna Kendrick (Camp, Twilight, Pitch Perfect) for Funny Or Die.com, both events of which has more or less garnered attention to f(x) in the US.

Korean Discography:
  • LA chA TA single (2009)
  • Chu~ single (2009)
  • Nu ABO EP (2010)
  • Pinocchio (2011)
  • Hot Summer (Pinocchio repackage, 2011)
  • Electric Shock EP (2012)
  • Pink Tape (2013)
  • Red Light (2014)

Japanese Discography:
  • Hot Summer single (2012)

Tropes related to f(x):

  • Action Girl - Luna.
  • Affectionate Nickname - The members call Luna "puppy" and Amber "koala".
  • Afraid of Needles - Victoria.
  • Animal Motifs - Amber once said in an interview that she's a Koala, Victoriaís a hamster, Krystalís a tadpole, Sulliís a penguin, and Lunaís a puppy.
    • Fans have also jokingly said that Amber resembles a llama and she's accepted it, to the point where she's adopted "llama" as her new nickname.
  • Ascended Meme - The fans calling Amber "llama". It's now part of her twitter username (llama_ajol).
  • Bifauxnen - Amber, the one with the most fangirls.
  • But Not Too Foreign - Krystal and her sister Jessica was born and raised in America, therefore making her Korean-American. Same for Amber, who was born and raised in America to Taiwanese parents, making her Taiwanese-american.
  • Cooking Duel - There was one in the 12th episode of Koala, in which Luna and Sulli (who made a rice cake soup) teams up to go against the team of Victoria and Krystal (who made kimchi pancakes). The duel was peaceful, though.
  • Cool Big Sis - Amber's sister Jackie and Krystal's sister Jessica.
  • Cosmetic Award - The reward in their last mission in Koala? A piece of cardboard with the words "End of broadcast. You have done well".
  • The Cutie - Sulli is f(x)'s resident fake maknae (Krystal is younger, although she and Sulli are considered the same age in Korea). Some people insist that she, Sulli, is the actual maknae, mostly because she looks (and acts) younger than Krystal.
  • Dark-Skinned Blond
  • Darker and Edgier: Their album and title track "Red Light" has a darker concept compared to previous albums.
  • Denied Food as Punishment - The consequence in the 7th episode of Koala, in which the first person to find the Egg Pie shop gets to buy... well, an egg pie. (In the other episodes, they sometimes compete against each other to get the prize money which would be used to buy food).
  • Even the Girls Want Her - Amber, of course.
  • Fake Memories - For 24 years, Victoria thought she was O blood type and realized her real blood type is A only recently.
  • Family Business - Krystal's older sister Jessica is a member of the girl group SNSD.
  • Fangirl
    • Amber is a big fan of Linkin Park's Mike Shinoda, and when she was a kid, she tried copying his voice.
    • Episode 3 of Jessica & Krystal shows that Krystal's a huge fan of Pharrell Williams, Frank Sinatra and even her sister and SNSD.
  • Food Songs Are Funny - Ice Cream.
  • Friend to All Children - Luna gets along well with kids.
  • Fun With Palindromes - Krystal's Korean name.
    "From the front, it's Jung Soo Jung. Say it backwards and it's Jung Soo Jung. My name is Jung Soo Jung!"
  • Genki Girl - Luna. She's the "energy pill" of the group.
  • Girl Group - A Korean Pop Music example.
  • Gratuitous English - Of course - this is a Korean group we're talking about, after all. The English lyrics are usually found in Amber's raps.
  • Hates Being Touched - Amber.
  • Kuudere - type two, Krystal is often mistaken as The Stoic and called an "ice princess" but despite her cold appearance her personality truly is warm. Krystal and her sister Jessica have said that hearing people call them "ice princesses" makes them really sad and even stated that the reason behind their reality show Jessica & Krystal was to dispel that idea and to show that they're really shy and quite playful.
  • Multiethnic Name - Chrystal Soo "Krystal" Jung and Amber Josephine Liu
  • Multinational Team - Let's have a recap: Victoria is Chinese, Amber is a Taiwanese American, Luna and Sulli are Korean, and Krystal is a Korean American.
  • Not So Stoic - Ice Princess Krystal. It runs in the family. Watch f(x)'s shows and you'll find out that she and her members are actually very nice and energetic. Also see the Kuudere entry.
  • Older Than They Look - Sulli has quite the babyface. Even though she's actually about 7 months older than the youngest member Krystal.
  • Peek-a-Bangs - Amber in the LA chA TA music video.
  • Retraux - The style of the "art film" for their 2nd full-length album Pink Tape.
  • Put on a Bus:
    • Amber was once absent from activities due to her ankle injury, and it went on for more than 6 months. The long absence lead fans to speculate that Amber had a dispute of sorts with SM (there were allegations she fought with another member and debated leaving, but this was never proven), thus lead people to think that f(x) would have their comeback with only four members. Fortunately that wasn't the case.
    • Sulli started her hiatus in mid-2014, following massive flack she was receiving for all kinds of reasons. This also meant halting group activities immediately (despite that the group was leading a successful comeback with "Red Light").
  • The Reveal - Krystal revealing Amber's middle name in Hello f(x).
    • Amber's somewhat okay with it now, though.
  • She's Got Legs: All have pretty legs and mostly aren't afraid to show them off. Even Amber's doesn't mind showing them off now and then
  • Shrinking Violet - Krystal. On the first episode of Jessica & Krystal, Jessica even revealed that when Krystal was young she would cry when people even looked at her.
  • Silly Love Songs - Chu~
  • Spell My Name with an "S" - Krystal. Her name is not Crystal. And definitely NOT Christal. Her birth name is "Chrystal", however.
  • Spoiled Sweet - According to fans, Luna and Victoria are very sweet and approachable.
    • Team Mom Victoria is very nice and amiable, of course. In their show Koala, she bought ice cream for the filming crew while she and her members shared one ice cream bucket.
    • f(x) as a whole is very sweet. Watching their shows are quite heartwarming.
  • Stage Names - "Victoria" for Song Qian, "Luna" for Park Seonyoung, "Sulli" for Choi Jinri. Krystal could count if you consider her birth name, Chrystal.
  • Surprisingly Good Foreign Languages
    • Surprisingly Good English - Krystal, who was born in California. They moved to Seoul in 2000 after her sister Jessica was scouted by SM. (Krystal was too young to be scouted at that time. She was scouted in 2006)
      • Amber counts too, because she also grew up in America.
    • Surprisingly Good Chinese - People who aren't avid fans might think that all the members of f(x) are Korean. That's not true - Victoria grew up in Beijing, and Amber's parents are Taiwanese. Victoria is fluent in Mandarin Chinese, Amber, on the other hand, has conversational fluency in said language.
      • Amber is a Cantonese speaker as well.
  • Surreal Music Video
    • Not an official music video, but the teaser / "art video" for Pink Tape. Try to decipher what the heck's happening in the video.
    • As well as the teaser and music video for Red Light.
  • Take That - To the too-high standards of the South Korean celebrity industry. Blink and you'll miss it, but here it is, from the ending credits of Koala episode 11.
    Sulli: South Korea is so picky about being skinny, that's why you can't develop/grow anymore!
    Luna: We need to have some fat!
    Sulli: Don't you agree? Everyone's so skinny!
    Victoria: We should stop here... (laughs) Please edit this out!
  • Team Mom - Victoria, who cooks and does the grocery shopping for the members. She's endearingly called "Vic Umma" (mother). During her time in the show We Got Married, the other members even treated her partner Nichkhun (of 2PM) as their dad.
  • Teen Idol Teen Idols - Just about everyone were in their teens when they debuted as idols.
  • Tomboy - Amber, and their stylists really like to emphasise this. She prefers to dress more boyishly such as baggy shorts and loose clothing, has Boyish Short Hair, and used to play a lot of sport when younger (which is how she adopted her tomboy looks in the first place). It's to the point that when she once grew her hair out it was interpreted as a Girliness Upgrade.
  • Travelogue Show.
    • In Hello f(x), they went to Africa for a photoshoot, to Thailand to perform in the Pattaya Music Festival, and to Japan (along with label-mates SHINee) for the ''Boys Over Flowers'' promotion.
    • And then there's Koala, in which they went to 5 countries to promote Korea's culture - although it sometimes looked more like a cooking (and eating) show than a travelogue show...
    • Amazing f(x) is this as well.
  • Unperson - This was done to Amber when she was recovering from her ankle injury, which went for over 6 months. When f(x) was filming Koala, because she wasn't part of it, video footages of the members talking about Amber were edited out and it went as far as asking a Hong Kong fanboy that they were filming to take down his poster of Amber. She also wasn't included in the 2011 f(x) calendar.
    • Since her hiatus from F(x) and the industry (with brief appearances to promote movies she'd already filmed prior and a red carpet event), this has been Sulli's role recently.
  • Who Wears Short Shorts?: Victoria, Krystal and Luna mostly alternate on who wears them (it's most common Krystal and Luna, when Victoria wears hotpants, the other two get the tight pants). Sulli often sticks with skirts and Amber only wears pants and long shorts.
  • You Gotta Have Blue Hair - Luna in the Pinocchio music video and again for Red Light.
  • Younger Than They Look - Krystal. She was only 14 years old in the LA chA TA music video, which was released in September 2009. Contrast to Sulli, who is 7 months older yet on the other hand has quite the babyface.
  • Zettai Ryouiki: Luna, Krystal, and Sulli are grade C in "Rum Pum Pum Pum", while Amber is grade D.