Memoriae Mori

Faceless corpses are being found in the city. Although two of the victims were students, their families didn't seem to be very upset. This catches the main character's attention, but her focus soon turns to those around her: a foreigner who suddenly transfers to her school, her sister who starts acting strangely, and a mysterious girl she encounters. While the main character tries to manage her personal life, in the city, people continue to die.