On March 14, Amber worried fans with a cryptic Instagram post that expressed her frustration. Many believe the message regards her label SM Entertainment.

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Under the post, Luna left heartwarming words and commented, "Koala let's cheer up. You know I love you, right? We're going to do well ?"

The last time f(x) released an album was in October of 2015 with ''Four Walls''. The girls have been focusing on individual promotions since then.