sad story about a normal guy that got forced by his parent to get married and actualy comes to believe that the girl he will choose is interested in him for being him and not a scheming cunning calculating gold digger
From the manga trope I've read it is probably a girl with no character or a girl that is unnoticeable, and you know who fits both of those criteria? the maid
The fact that Natsuki left the letter when the maid visited means that the maid is it but it’s really bad or that it’s not the maid but rather a servant for Natsuki.