A strict, by-the-book, bespectacled instructor at Futatsubashi Elementary School, who has gained a reputation as a fearsome authoritarian figure among students and staff alike. As the daughter of two teachers — one of whom has since gone on to become the chief of the board of education — it might come as little surprise that Sae Shirai would become one herself were it not for the fact that she hates children and eschews social interaction.