Airi Hiraga

Airi Hiraga is a second year that Yama has happened to know about, due to a certain stir of events. She is mainly known to be a subject to several rumors in the academy as the murderer of the victims. 

She is also a gamer, and it turns out that she has played games a rather long time ago. She happens to have a short stature (according to Yama, two heads shorter than him).