Shikishima Nao

Shouta's classmate and long time friend, even after advancing grades and schools they have always been in the same class.
She has known Shouta for a long time and even lives near him, and while she is his only female friend they're relationship is close enough that he will consult her rather his male friends.

Nao has been giving Shouta advice for a long time and is happy to do so, she is one of the few people who knows why he was kicked out of his house.
She has always assumed Shouta has an extreme Oedipus complex.