The second teaser video of the new song ‘Favorite Boys’ was released on the official SNS of A.C.E on September 1st at 00:00. In the released video, the performances of the Ace members caught the eye. In particular, A.C.E's unique group dance performance was partially revealed along with various styles of costumes that made use of individual members' individuality, and the expectation for the new song 'Favorite Boys', which met a unique 'Kalgunmu(dance)' and an unrivaled concept, was further raised.