After debuting at number 14 last week, five-piece girl group f(x) stormed into the number one spot on the Billboard K-Pop Hot 100 with their infectiously rhythmic single "Rum Pum Pum Pum" off of the album "Pink Tape."

The band also scored the most downloads in the first week for a song so far this year for "Rum Pum Pum Pum" with 1,690,748, according to the website Popdust.

This year's precious record holder for first week downloads was fellow girl group 2NE1, who earned 1,244,916 downloads for their song "Falling In Love."

Crayon Pop's single "Bar Bar Bar" is also a major chart climber this week.

The song rose to number two on the Billboard K-pop chart in its fifth week on the chart, after spending last week at number six.

"Bar Bar Bar," which topped several South Korea pop charts this week, could have been bolstered by a wacky instructional video for the song that the five members of Crayon Bop appear in this week.

The five-and-a-half minute clip, which features the five-piece girl group doing their choreographed dance moves in crash helmets has received over a quarter million YouTube views in three days.

And speaking of crashing, the accident-plagued singer Ailee fell two places this week.

Although she had held strong in the number one position on the Billboard K-pop chart for two weeks, Ailee slipped to number three with her song "U&I."

It is the fourth week on the charts for the song "U&I."

One place lower than last week, is the gothic single "Shadow" by BEAST.

The video for "Shadow" is one of the best the genre has seen all year.

With apocalyptic CGI effects mixed with creepy stripped-down footage, it is an impressive clip.

And debuting in the Billboard number five spot is rapper and producer San-E with his song "Story Of Someone I Know."

The song is the title track off of San E's new album, which was released on August 2. The music video also stars Nara of the girl group Hello Venus.

The rapper and songwriter left his record label JYP Entertainment in June and joined the Brand New Music roster in June, according to the website allkpop.

Click here to read the full results of the Billboard K-Pop Hot 100