[Matsui belatedly realizing that this is an incredibly smart idea and maybe he too should have pretending to be Amakusa Shiro.]

Ah. [JUST "AH". Oh well, too late to do anything about it now when a good handful of people have already gotten his honest introduction. He'll move right along.]

That isn't an unwise thing to do... Though I don't believe I have ever met someone who uses a codename at all times because of their job. Even among comrades, do you go by "Courier"?