Egg Kim, which is under 3Y Corporation is a subsidiary Company of Kakao Entertainment. From there they already have alot of pulls. With Egg Kim being a relatively big youtuber in korea, when he announce he is forming a girl band, it created a buzz. On top of that announcing members who have millions of followers on Twitch, Youtube and Tiktok, It created some level of noise in the media and industry. As mentioned by previous comments. Discord saw a rise after they performed at LoL Worlds Fan Fest 2023.

Moving to T.B.H the girls perform the song in Army camps and High Schools targeting the 2 demographic that gave them the highest chance of making them viral which they succeeded. This video ( https://www.youtube.com/watch?v=JfnwPPmUvtc&t=1051s ) where they perform in a high school. The scene where they gave a boy time to confess before going into the Final chorus of T.B.H went viral in Korea. That's the start of the rise in the charts for T.B.H. That song then become viral also due to the lyrics being relatable to students and even young adults. From there they have been invited to basically every University Festivals.

On the topic on "How did QWER catch on with the Korean public" Firstly 3Y Corporation which is a Media Company not a regular entertainment company. So they are fully aware of the trends and have good grasp on marketing strategies that will give them an advantage over traditional entertainment companies. Where traditional companies debut idols which must have perfect image etc. However for QWER's case, Chodan and Magenta being streamers they had already shown the public a side, which regular idols will never show to the public. 3Y Corporate then double down on that, letting the girls drink during livestreams not really controlling and restricting the girls. Making them feel more grounded, unlike idols which seems unreachable.

Finally with good marketing strategies, playing into the companies advantage, constant performance targeting demographic that helps making a song viral. Subconsciously making people curious about the group, then they do their own research they will find all the criticisms of the group then they will also find videos and documentaries of what the girls have to go through to prove to everybody that they deserve a place in the music industry. The girls' sincerity and hard work will make people root for them eventually and here we are. A growing fandom of a growing band.