Examples of "teen" concepts
The most popular 4th gen girl groups IVE and Newjeans, both have different versions of this teen concept. IVE are more luxurious while Newjeans is fresh and bubbly. The girl group that arguably opened 4th gen, ITZY, debuted with a "teen crush" concept. I find it interesting that this concept is so popular now because it was virtually nonexistent in 2nd gen and only a small handful of 3rd gen groups tried it(Weki Meki actually coined the term "teen crush.") Doubly interesting is that IVE and Newjeans fanbases mostly consist of teenage girls and women in their 20's. This is opposite to 3rd gen where the popular girl groups fanbases mostly consisted of men. So I wonder if the rise of the teen concept has something to do with the majority kpop's audience now being young girls and women.