2nd Gen Girl Groups: The Women Who Changed Kpop Forever!

2005:

The Grace (SM Entertainment)

2006:

Brown Eyed Girls (Nega Network)

2007:

Girls Generation (SM Entertainment)

Kara (DSP Media)

Sunny Hill (For Everyone Media)

Wonder Girls (JYP Entertainment)

2009:

2NE1 (YG Entertainment)

4Minute (Cube Entertainment)

After School (Pledis Entertainment)

f(x) (SM Entertainment)

Rainbow (DSP Media)

Secret (TS Entertainment)

T-ara (MBK Entertainment)

2010:

Girls Day (Dream T Entertainment)

Miss A (JYP Entertainment)

Nine Muses (Star Empire Entertainment)

Sistar (Starship Entertainment)

2.5 not included. Every group that debuted after 2010 were extensions of these founding groups who shaped kpop into what it is today.