Summer Nights is TWICE's 2nd Special Album, released July 9, 2018 through JYP Entertainment. It serves as a repackage of their 5th Mini Album What Is Love?, adding three new tracks — "Dance the Night Away," "CHILLAX," and "Shot Thru the Heart" — for a 9-track total. It comes in three versions — A, B, and C — each including a photobook, CD (1 random of 9), 5 photocards (5 random of 90), a message photocard (1 random of 9), a lyrics poster, a polaroid postcard (1 random of 9), and a DIY paper postcard. Notably, "Shot Thru the Heart" was co-written by Japanese members Momo, Mina, and Sana, and "HO!" by Jihyo. A monograph was released December 31, 2018, featuring a 150-page photobook documenting the "Dance the Night Away" music video shoot in Okinawa, Japan, and 9 signed member photocards.