Sexy factor.
Sexy factor.
If it's not Isuzu-chan Mii~
More than a mask.
Looks more feminine/princess-like. The pale/weak/sickly presentation also has its appeal at times in culture I think.
From a story perspective, a handkerchief let's her take it on/off rapidly, leading to scenes like her sniffing MC out. If an effective mask was worn, she wouldn't catch into the fact that MC didn't smell bad.
If it's not Isuzu-chan Mii~