TRIGGER WARNING: This manga has a "nice" rape plot for one of the characters. Talk of rape and violence.
So the big story that starts this manga is a girl that was raped when she was around 10, so now she feel dirty. Now that she feels dirty and broken she's going around having sex with random men and it's just a mess.
The book is also trying to make her out to be 'a bitch' and Kureha? dumps a bowl of hot ramen over her head and it's seen as perfectly OK.