f(x) originally debuted as a five-member band. Reuters

It's been seven years since f(x) stepped into the world of K-pop music with their first album, LA chA TA in 2009. Since their debut, f(x) has released four full-length albums, two extended plays, and one repackaged album.

Till now, the year 2016 has been wonderful for the girls from commencing their first concert tour to releasing an EDM track, All Mine. The girls have remained strong all the years and are proud to complete the seven long inception year of their wonderful bondage in the field of music. Recently, two of the four members experienced an emotional rush and posted heartwarming messages to mark their debut anniversary.

The American-Chinese descent rapper of the group, Amber, posted an old picture of the band and thanked her fans for all the love. She said: ""Lucky 7! Always thankful to all the MeUs out there who've always had our backs. But on the real though... We getting old XD Never gunna stop the grind and always gunna work hard for all you guys!!! [sic]."

While, Krystal, who is currently sharing her romantic side with EXO's Kai, posted a message on the group's official homepage.

"MeU, have you been doing well? It's been too long, right? I don't know how many times I've erased and rewritten this. I'm embarrassed and apologetic because I feel like I'm saying the same things for the seventh year in a row. I will always feel thankful towards you all who have consistently loved and supported me regardless of the many things that happened over the last seven years.I promise to repay fans the amount of love [you have given us till now]," she wrote.

The SM Entertainment girl band consists of four member, namely Victoria, Amber, Luna, and Krystal. However, the fifth pillar of the band, Sulli, left the group in 2015 to solely focus on her acting career.