When they first debut, K-Pop idols are referred to as rookie idols or newcomers. At annual award shows, there is usually a Rookie Of The Year award that is won by idols who have become popular since their rookie days.
According to Koreaboo, when K-Pop idols receive the Rookie Of The Year award (or similar) at five major South Korean award shows such as the Melon Music Awards, MAMA, Golden Disk Awards, Circle Chart Music Awards, and Seoul Music Awards, they will have the title of Rookie Grand Slam. This title is very rare for rookie idols to achieve, and currently, there are only seven K-Pop groups who have successfully achieved this title.
Instead of being curious about who the Rookie Grand Slam groups are, let's directly read the article, Klovers!