Fin.K.L member Sung Yuri returns to the music scene after 5 years. Recently, Sung Yuri has secretly recorded a duet titled ‘Lovers Declaration’ (연인 선언) with singer, Tim. According to Sung Yuri, although she felt a bit embarrass as she has not recorded any songs for a long time, she still completed the job happily. Both of their sweet and charming voices mingle in this duet track.