Summer Nights is the expanded reissue of What Is Love?, the fifth extended play release by South Korean girl group Twice.

[2][3][4][5] On June 7, 2018, JYP Entertainment (JYPE) confirmed that Twice was scheduled to make a comeback in July and that the music video for the lead single was filmed in Japan.

[6] Later that month, it was officially announced that Twice would release a special album titled Summer Nights, a reissue of their fifth extended play (EP) What Is Love?.

[7][8][9][10] A short video preview of the three new songs was released on July 8.

[1][12][13][14] On June 19, 2018, it was confirmed that Twice would guest on Idol Room, the group's first variety show for their comeback with Summer Nights.