How would the students react? Specifically, how would your favorite girl react? Assuming this doesn't effect anything outside of Yamaku, so all the missing family members remain missing, what would the toll be on the psyche of, say, Lilly, who's been blind from birth? Suddenly gaining a new sense is almost undoubtedly disorientating. Shizune can't switch off her ears; how would she react to suddenly being capable of hearing?
To put it simply, I think Emi and Lily would be the most calm about the situation. Emi already had legs and so would be shocked to find them reattached, but I can see her gripping the situation within minutes of the Event.
Lilly would probably be unable to cope with being Sighted, but she can at least close her eyes and essentially turn the sense "off". I imagine she'd wait until she was alone to stumble about and figure out how depth perception works, and look at letters. I think she'd probably enjoy having the new sense, but as with Shizune it sort of makes her her, so she maybe wouldn't be too overjoyed.
Shizune would probably get a massive headache. Suddenly she can hear sounds, and I imagine her ears would be relatively sensative, or at least seem that way because HOLY CRAP THIS IS NEW. Combine with everyone freaking out and Misha sitting next to her and she'd get overloaded pretty quick. I would kind of like to see her face the first time she uses her snap with working ears though.
Rin would... It's kind of hard to think of what Rin would do. She would certainly find her new limbs quite unweildy and possibly even bulky. She may put herself off balance every time she swings her arms. I don't see her flipping her lid though, like probably some of the other students would be doing. Rin just isn't like that. I see her more just... staring. With her mouth open. Wondering what the hell arms are doing on her body. She'd probably still use her feet for most things though; she doesn't know which muscles to move to make her arms to more than roll her shoulders. After she figures them out though she'd probably just go around feeling things with her fingers, weirded out and kind of entranced by new sensations.
And yes, I am the same guy who just asked this on /vg/ a few minutes ago. I just thought of the idea and I don't want it to vanish into the perilous depths of my "memory". By which I more accurately mean "Pulsar" because the only thing that escapes it are pulses of light to reveal things I've forgotten Too Late.
She's rather cute either way. Deus Ex can't change that.