Written by Park Chang-hyun and produced by Lee Soo-man of S.M. Entertainment, "Hug" was first performed at a joint showcase featuring label mate BoA and American singer Britney Spears on December 26, 2003, TVXQ's official debut day.
Ditulis oleh Park Chang-hyun dan diproduksi oleh Lee Soo-man dari S.M. Entertainment, "Hug" pertama kali ditampilkan di showcase bersama menampilkan rekan satu label mereka BoA dan penyanyi Amerika Serikat Britney Spears pada tanggal 26 Desember 2003, hari debut resmi TVXQ.