Can you help me find this Manga?

About 10 years ago I was reading this series but I couldn’t find anymore after book 3 or 4. I’m 90% sure I was able to buy it at books a million but I could be wrong. 10% of me questions if I actually bought it from a used book store. Either way, if anyone could help me find it, that’s be super. Google wasn’t helpful. I’m pretty sure the title of the series was like “K.O. Highschool” there might’ve been more but it definitely had K.O. Highschool in the title. The main character was a female and she was like BEAST at her high schools K.O. Fights. Can’t remember her name but I think it started with a K? She also worked at this cafe on the side and that was like a secret she was trying to keep. Any help would be great! Thanks!

 

was it about actual fighting or video games
https://en.m.wikipedia.org/wiki/High_Score_Girl

looks like this manga is about video game