We know Vermouth's mother is dead all right. We know the organisation is after some sort of immortality-giving item all right. We know Nana to no...the crow song is about a crow mourning her death child all right (or somethning like that, I don"t remember well). Lasly, we know Vermouth is the boss' favourite.
Here is my theory: Anokata is
Vermouth's father! She is so obviously his favourite, and he might want to search after something that gives everlasting life to ressurect his lost wife!
Your thoughts?
PS: Sorry for my rushy writing, I'll try to develop in my next posts