The Super Junior duo released their digital single called '떴다 오빠 (Oppa, Oppa)' on December 16, 2011, through various Korean music portals like Melon, Bugs, Mnet,etc... and they presented the song on December 16 in Music Bank. The song was first introduced in Super Show 4 on November 19, 2011. A month later, SM Entertainment announced that Donghae and Eunhyuk would promote the song in several shows like Music Bank, Music Core, Inkigayo, M! Countdown, among others. The song's music video was released on December 16, 2011. A second music video was released on December 21, 2011 which was edited and directed by Shindong, another Super Junior member. Amber of f(x), Peter and Youngsky of One Way group and Sungmin and Shindong feature in the music video.
The single includes two songs, the song "Oppa, Oppa" and "First Love". "Oppa, Oppa" reached 2nd place on Oricon‘s daily single and weekly charts, and #1 on Tower Records‘ single chart.
Peter of Team One Sound wrote, through Twitter, that the duo would release new material in 2013. On June 19, 2013, the duo released their second Japanese single "I Wanna Dance" which also includes the B-side track "Love That I Need" featuring Super Junior-M member Henry.
They released their second Korean single "Still You" on December 18, 2013. The music video for "Still You" was filmed in London.
