The album is mostly synthpop, with the title track, "Mr. Simple", being the last installation of the "SJ Funky" genre in which the group has been consistently pursuing since "Sorry, Sorry" (2009) and "Bonamana" (2010).
Album ini sebagian berisi synthpop, dengan judul lagu, "Mr. Simple", menjadi instalasi terakhir dari genre "SJ Funky" di mana kelompok telah secara konsisten mengikuti sejak "Sorry, Sorry" (2009) dan "Bonamana" (2010).