Maybe she's written as a foil to the MC? He also sucks at human interactions, thinks it's appropriate to talk abou torture methods in the classroom and misinterprets other people intentions but since he dropped off the assassination scene he gotten the chance to be inserted into society and live as a normal citizen. As Ayamu still is an assassin, she really doesn't have the grounds to understand people. I don't know if it was the author interaction since the text doesn't make clear parallels but hey, meaning is meaning and meaning is preferred to meanless.