Taemin joined the reality show The Unit as a mentor in October 2017. His second studio album, Move, was released the same month. Its lead single of the same name gained attention for its unique choreography and sparked a trend called "Move Disease" after a performance of the song went viral in South Korea. The album debuted at number two on the Gaon Album Chart and number three on the Billboard World Albums Chart. On December 10, a repackaged edition of Move was released, titled Move-ing. It added four new songs to the tracklist, including the lead single "Day and Night". That same month, Taemin was scheduled to perform at the annual KBS Song Festival but pulled out a week after the death of bandmate Jonghyun.
