"What's your number? Hello, we are SECRET NUMBER!" SECRET NUMBER (시크릿넘버) is a five-member girl group under Vine Entertainment. They were originally set to debut on March 26, 2020, but it was postponed due to the worldwide outbreak of COVID-19. They debuted on May 19, 2020 with the single "Who Dis?".
They had their first comeback six months after debut with the single "Got That Boom" on November 4th, 2020.