Again (T-ara EP)

Again is the fifth extended play by South Korean girl group T-ara, It was released on October 10, 2013 by Core Contents Media. It marked their first release with the original line-up following member Lee Areum’s departure from the group. It is also the first official release without Ryu Hwayoung's vocals being featured.

"AGAIN 1977" is a repackaged version of "AGAIN." It features a retro concept with a blend of pop and rock influences. The title track, "Do You Know Me?" showcases the group's versatile musical style and is known for its catchy melody and upbeat vibe.

Again
The album was released digitally on October 10, including the title track "Number 9" (넘버나인) and "Because I Know" (느낌 아니까; Neukkim Anikka) and their music videos. "Number 9" is an electro-pop dance song with sad lyrics and melody. It was choreographed by Yama & Hotchicks, who also choreographed "Bo Peep Bo Peep". "Because I Know" is a mid-tempo song with an acoustic feel.

Again 1977
A repackaged edition of the EP, Again 1977, was released on December 4, 2013. It contains two new songs, "Again 1977" and "Do You Know Me", a remake of Sand Pebbles' 1977 hit, "What Should I Do".

White Winter
The EP was re-released as special album on December 14, 2013 titled White Winter with additions two Christmas songs, "Hide and Seek" and "Middle of Winter Hide and Seek".

In 2016, Chinese girl group "Miss Mass" released a remake version of the song in Chinese.

Commercial performance
Shortly after its release, "Number Nine" reached number one on multiple real-time charts.

Again reached number 2 on the South Korean Gaon Weekly Albums Chart and number 45 on Japan's Oricon Weekly Albums Chart as a Korean import. The single "Number 9" reached number 5 on the Gaon Weekly Digital Chart and number 4 on Billboard's Korea K-Pop Hot 100. "Because I Know" charted at numbers 41 and 21 on the Gaon and Billboard charts, respectively.