On January 13, 2017, Brave Entertainment announced that member Yujin would be leaving the group while Hyeran would go on an indefinite hiatus due to her health worsening. The following month, it was revealed the group would be making a comeback in March as a five-member group. A comeback schedule was released on February 27, 2017 for their fourth mini album, "Rollin'", which was released on March 7, 2017.