[That was right... the Postal Mistress Ribbons was so fond of. Not that Tieria had a problem with her... just that she and Ribbons seemed to have developed an unexpected relationship. That was neither here nor there at this point, however, with Ribbons gone from the dome... Tieria just had trouble letting things like that go at times.]
Yes. I would imagine she would know quite early if anyone is missing. Though, I do not believe Setsuna would have relocated his living arrangements without informing me first.
[Yes, he was overdoing the formality in his speech on purpose... it was helping him cover what he really wanted to say and ask.]