//Roger that!
//In that case, yes, I think pretending to wake up is the best course of action, since it comes with the plausible deniability that we didn't respond the first time because we were asleep. Then we can undo all the changes as soon as they ask, including an apology for upsetting Ran so.
//An alternate possibility is removing everything and then manifesting and claiming a delay due to needing to work up the magic to undo everything. This may add the additional irk of spying on them, but it should at least mostly smooth things over.
//I imagine there are other, similar possibilities at our disposal, and am not so attached to what I proposed that I am only willing to accept that one course of action. What I do not believe should be done is any course of action that gives away that we heard Yukari's request and intentionally didn't act on it, since she has already bought the idea that we weren't present to hear it.
//Fake Edit: Claiming a prank is also a possibility (no actual harm has been done), though it would be best framed as a prank gone too far, with an apology attached. This could work with the alternate possibility described above. I like this idea less, but I don't dislike it. I'm not really sure I understand the rest of what you're asking, though.