It was announced on September 26, 2013, during the event E.L.F-JAPAN FESTIVAL 2013 that Super Junior would be releasing their fifth official Japanese single, "Blue World", in December 2013.
Pada tanggal 26 September 2013, selama acara E.L.F - JAPAN FESTIVAL 2013 diumumkan bahwa Super Junior akan merilis single Jepang resmi kelima mereka , "Blue World", pada bulan Desember 2013.