Jeez I’ve heard of thick thighs but…well I mean I can’t say I haven’t seen thighs that thick. I can’t even say I haven’t seen at least a couple girls with upper bodies almost that skinny and thighs that or almost thick.
It’s just highly unusual, and likely a disorder of some kind. They usually have trouble walking lol
Also it’s usually not just their thighs. But this is anime.