I haven't read love attack . . . And think you are on the wrong chapter (I think) since this one is where they just found out Aizawa is a she and didn't seen anyone wearing a headband . . . HOWEVER, I love you for mentioning that because that looks like a manga I might really enjoy ^_^, love longer series, and can't believe I missed a 13 volume, completely translated series like that . . .
Anyways, why the hell didn't she just toss a shirt on right away, she is flat anyways, it isn't like they would notice. Also, why didn't she just go back to the dorm and change? I'm assuming it is only 5 minutes from the school, so she would be like 10 minutes late tops. Which is a whole lot better than her secret being exposed.