A Bias Girl

A Bias Girl is a Korean manhwa written by Wie Sung-soo and illustrated by Kim Soo-min.

Plot
The antics of two high school girls: Kim Peongyon and Choi Boa. Kim aka "Bias Girl", is a foul mouthed, overactive girl and idiot who weird and strange, bias ideas on people and things and Boa is smarter and saner of the two who plays the straight girl every time Kim does anything stupid.