The release also showed a big transition from the group's original "strong female" image to a "cute and natural" appeal, shifting from the R&B sound of their debut to bubblegum pop.

After a 10-month hiatus, Kara returned with 2 new members: 17-year-old Goo Hara and 14-year-old Kang Jiyoung.

They replaced Kim Sunghee, who left for educational purposes.

A remix version of the song "What's This" entered in the special edition of the group's second EP "Pretty Girl".

The album entered at number 81 for the second week of 2010 on the Gaon Album Chart and peaked at number 8 for the week ending July 3, 2010.