That under the tatami angle was mean... and lets me think she wasn't 5 kg only due to the pounding sound she makes while walking.
Also I don't know if she had lost her weight for a long time (or don't remember), but if she did, she should have had a schock when getting it back. As much as the guy suddenly jumping from 55 to 100kg.
The mood change, well I was a bit annoyed at first. Depends on the quality of the show from now on.
Anyways, I prefer the class rep for the moment, eventhough her screen time was short.