Oh Seung Ah

Seungah debuted as a member of Rainbow on November 12, 2009 with the group's first mini album Gossip Girl. She debuted as a member of Rainbow's first sub-unit, Rainbow Pixie, on January 12, 2012 with the digital single "Hoi Hoi". On January 20, 2014, she debuted as a member of Rainbow's second sub-unit, Rainbow Blaxx, with the special album RB Blaxx.

On October 28, 2016, DSP Media announced that Rainbow would be disbanding after seven years of activities after all of the members decided not to renew their contracts with the agency. Following her departure from DSP Media and Rainbow's disbandment, Seungah signed on with MADA Entertainment, then known as GnG Production. In 2019, Rainbow reformed to celebrate their tenth-anniversary since debut with the special single album "Over the Rainbow".