I think he meant more like a married wife (in this case hubby xD) kinda way, but im not 100% sure
i think Asami let it be known that Takaba was to be addressed as such. Half as a joke maybe to get under Takaba's skin, half as a subtle hint. It also tells the reader that no one comes from that apartment But Asami. How would the guy know who Takaba was unless Asami or someone working for him told him? hahahaha
I don't get the scene. At first, I thought why would that guy call Aki Asami sama? Maybe he mistook Aki for Asami but Asami's build is huge and he wouldn't go out in that getup. I then thought that it was meant as a tease since Asami knows every move Aki makes and he wanted that receptionist to mistake Aki as Asami on purpose.
I think it is Asami's idea at the frist place to let them know Akihito as Asami.
Think so too, since Aki blushed
Given Aki's visions of serving dinner in an apron, I am sure being Mrs. Asami is not high on his to-do list. :)
Right after Aki moves in with Asami, the guy at reception calls Aki "Asami-san":
http://www.mangago.me/read-manga/you_re_my_loveprize_in_viewfinder/mh/v06/c035.2/8/
Is this just because Aki is coming from Asami's apartment, or did Asami tell the building management Aki was "family" or what?