To the ones checking the comments section because of the tags (and don't mind spoilers) and those who don't really get the story, the story is basically about a girl who made a promised to kiss her friend, but got raped and then avoided the promise because she believes she's dirty. Then she tried to wash away the experience of the rape by normalizing it by having sex as a call girl, which she believes will make her clean again so that she can fulfill her promise. But she haven't met her friend in while since she dropped out of school to be a call girl, and one day they finally met and she broke in tears after seeing her "angel".
I read it once and thought of it as a mess. After re-reading to try to understand the story, it's still a mess that I just understand better.