In 2009, Secret released their debut single, "I Want You Back". In 2010, they released two EPs: Secret Time and Madonna. In 2011, they released two singles, "Shy Boy" and Starlight Moonlight. In the same year, Secret also made their Japanese debut with their first single, "Madonna". They then released their first full-length Korean studio album, Moving in Secret, in October 2011. A month later, the group released their first Japanese EP, Shy Boy. In 2012, the group released two Japanese singles, "So Much For Goodbye" and "Twinkle Twinkle", prior to releasing their first full-length Japanese album, "Welcome to Secret Time". In September 2012, Secret released their third Korean EP, Poison, followed by their second digital single, "Talk That", in December 2012. In 2013, they released their fourth EP, Letter from Secret, and one single album, Gift From Secret. In 2014, they released two Japanese singles which were Japanese versions of "I Do I Do" and "YooHoo". Later that year, their fifth EP, Secret Summer, was released.
^"2011 Album Chart" (in Korean). Gaon Music Chart. Retrieved August 31, 2016.
^2012년 Download Chart (국내) [2012 Download Chart (Domestic)]. Gaon Music Chart (in Korean). Retrieved December 14, 2017.
^2012년 12월 Download Chart [December 2012 Download Chart]. Gaon Music Chart (in Korean). Retrieved December 14, 2017.
^2013년 Download Chart [2013 Download Chart]. Gaon Music Chart (in Korean). p. 3. Archived from the original on August 15, 2016. Retrieved December 14, 2017.
^2013년 Download Chart [2013 Download Chart]. Gaon Music Chart (in Korean). Retrieved December 14, 2017.
^2013년 12월 Download Chart [December 2013 Download Chart]. Gaon Music Chart (in Korean). Retrieved December 14, 2017.
^2014년 01월 Download Chart [January 2014 Download Chart]. Gaon Music Chart (in Korean). Retrieved December 14, 2017.
^2014년 Download Chart [2014 Download Chart]. Gaon Music Chart (in Korean). p. 3. Archived from the original on August 15, 2016. Retrieved December 14, 2017.