"Push Push baby!" are hummed by many K-pop fans today. The popular lyrics to their debut album "Push, Push" became an instant hit. With their recent foray into the K-pop world, they're pushing their success to new heights.

Before they were singers, these ladies were actually fashion models - albeit for a short time. Their first media appearance was a Céci fashion shoot in England for the clothing brand FUBU.

From left to right: Hyorin, So Yoo, Bora, and Da Som

"Push, Push" was a great start to their budding career, yet their third single is was cemented them as more than a "one-hit" wonder. With the release of "How Dare You", they soon received awards. The "newcomer award" by the Golden Disk Awards and won song of the week on Music Bank on December 17th 2010 were two of the major accolades they collected.

"How Dare You" is still played in regular rotation on Korean music stations, as well as fan sites as well.

In Janurary 2011, the decision to make a new sub-group with leader Hyorin and Bora was made. Called Sistar19, the "19" would symbolize the age. According to Starship Entertainment, "being 19 is considered youthful, innocent, yet becoming an adult as well." The irony is that both Hyorin (20) and Bora (21) are both older than 19.

This new subgroup was to showcase Hyorin's powerful vocals, while showing Bora's rapping and flow in their upcoming single.

Sistar19 is a sub-unit of Sistar. It features two members: Hyorin and Bora.

They released "Ma Boy" on April 27th, 2011. With the music video's body roll dance routine and R&B feel, the song quickly caught onto the Korean music and TV stations.

With their recent activities in the past month, expect Sistar to stay low and prepare for their next album.