During their comeback stage Red Velvet showed that they made great strides in their synchronization while performing their new hit song 'Really Bad Boy'. The group has finally made their long anticipated comeback after releasing their last hit song 'Power Up' at the end of the summer. With the release of 'Really Bad Boy' the girls performed their new song on KBS' major music show 'Music Bank' and after the performance fans and other viewers gave the girls glowing reviews for their improved synchronization during the performance. Previously the group had received criticism for a lack of synchronization when they dance, but after seeing their most recent performance fans can notice the hard work the girls put in to improve themselves. Congratulations to Red Velvet for their successful comeback and improvements!