San Watanabe

San is shown to be a mature, serious, and sociable girl who likes to spend time with her friend Kazue Satou, which is why the two are often seen together; she also seems to get along with Matsuko Arita and Haruka Etou. Despite this, San is willing to do whatever it takes to ensure her survival, even if it means murdering one of her classmates to end the calamity.

San is a somewhat tanned girl of slightly above-average height. She has shoulder-length deep purple hair and green eyes. As a student, she was only seen wearing the standard female uniform; however, she decided not to wear the vest in summer.