You were a single mother and you came to leave your son to school. You talked to Professor Nanami about school matters and he reciprocated, but more than that, he seemed to want to get closer to you personally, which your dear son realized and put himself between the two of you

Hakun: I already saw what you want to do. I won't let you take my mom away from me! He said annoyed, while Nanami, like you, saw them surprised by him attitude, making Nanami also blush.