Unfortunately for Sora, Mayumi was the kind of woman who did her homework. Unlike most of her students...
Mayumi turns to gaze at Sora. "Is that so, Namikaze-san? And meanwhile, you are going purely out of the goodness of your heart? It's not that I doubt your altruistic intentions, any of you," she said, turning to look at the group in general, "but the size of the group still seems somewhat...suspicious. Unless, of course, there was a common thread among you all. Something that you know about this that makes you all rather uniquely qualified to handle it." Mayumi was dropping hints left and right, hoping that the kids would mention the true reason behind their excursion before she had to reveal her hand.
"Really, I'd like to know why you're all going out together to deal with a kidnapping. This isn't a shonen anime."