Following a performance on Show Champion, Nana fell off the stage and suffered from severe shock and contusion to her pelvic region, which meant that she would be absent from promotions until she had fully recovered and the group therefore finished promoting "First Love" as 6 for the time being.
Mengikuti sebuah penampilan di Show Champion, Nana jatuh dari panggung dan menderita syok parah dan kontusi pada daerah pelvisnya, yang berarti ia akan absen dari promosi sampai ia sepenuhnya pulih dan mereka menyelesaikan promosi "First Love" dengan enam anggota untuk saat ini.