How did she knows that boy is fuutarou anyway? In past fuutarou's hair is blond, itsuki did not see fuutarou's photo yet, nino is the only one sees that photo but dosent know the boy is fuutarou.
who else can know that blond boy is fuutarou nowdays? is the one who reads fuutarou's student notebook and sees the photo completely (nino saw half of it)
Is there someone who can read the notebook besides nino? ichika is the strong suspect because, night before fuutarou come to claim the notebook, there is discussion between ichika and nino about ear piercing (chapter 14) there is possibility ichika can read that notebook if, the conversation held in nino's room