Erika, on Mikado
Erika is very good at seeing the truth behind a situation; she can sniff out lies pretty easily compared to your average person, and she’s very in-tune to the intricacies of social situations, other peoples’ feelings, and the world around her.
Her knowledge of literature has offered her a very expansive world view, and her acceptance of literary themes allows her to entertain all possibilities, not just those that are readily available.
... However, when it comes to Mikado, Erika is almost entirely blind. Her original impression of him as a timid, stuttering country boy has clogged her perception of him and the “layers” of his personality. Despite his complex history and role in the Ikebukuroian story, Erika can not view him as anything other than “Mika-boo! That guy who can’t even talk to girls!”
Essentially, Mikado is the only person who consistently pulls the wool over her eyes.