Responses
As a person who lived in japan...
Believe me, unless if you are anorexic, it is fat.
I am 161 CM and weighted 62 kg or so back then. Called me obese.
My coworker was 168 CM and weighted 58kg. They called her fat..
Even in other manga the girls are just skin and bones, mostly shoujo. The only meat they have are boobs, add or thighs.
Her height is 4'11" and she weighs 137 lbs. Like come on, NO ONE would be making fun of her weight.
Don't try to tell a 'fat girl' narrarive and then not even have the girl be fat.