It is hard or maybe impossible, would suit better, to find a good manga with a fat woman lead, well you have Cousin, but in that one, the character is far from being fat, she's chubby and a little fleshy, and her character is more likable, the story is less depressing.
In our story:
the protagonist starts weak and no matter that she decided to lose weight and actually did lose a lot, she still remained the same annoying weak woman, of course just because she became skinnier doesn't mean she have to become strong, what I mean is that after the 12th chapter, you would think somewhere she would do a little something different, "eh bien non", so I decided to give up. Indeed, she shows no sign of stopping to be a doormat to others, letting her colleagues and even her "so-called lover" treating her like a nasty piece of shit, because she was fat, and they keep treating her like garbage even after her weight-loss. She has no backbone, so far there is no character development for her, so when I saw that there were like 3 or 4 chapters left, I thought it didn't worth finishing it. I really thought, she would change just little by little, and of course I didn't expect her to fully become someone else, but "quand même", just a little something.
It is such a pity that when you have a manga with a big woman for a change, she is just shown as the worst protagonist ever or close, victimized as forbidden, bullied like an aloof pupil of junior 2ndary school who doesn't fit anywhere. There is a limit of how you can let people push you around, and just because you're unpopular doesn't justify the fact, and I really dislike when I see little evolution or progression, especially in this type of story.
She doesn't give me a single reason to feel sorry for her. I mean just because she's so insecure, she clings to her "man" (if he can be called like that, because he's more like a sex partner to me) like if he was some special prize, and she doesn't care about anybody except him. There's this woman colleague who tries to befriend her, and she also tell her that she should fight back her mean coworkers, all no to avail. So with that being said, it's kind of hard to empathize with someone who doesn't care for you concern.
It is interesting to have such a character, was what I thought when I decided to read this, but it failed somewhere.
The graphics really suits the story, the characters are drawn quite realistically to a certain extent, nobody is beautiful or close to. Concerning the background, it's really simple, there isn't much to say about it.
Overall, it is a pretty mature story, realistic to some extent, because it deals with serious matters such as bullying and eating disorders.