Habara's Senpai

She is a third-year high school student of Sanada West High School and an upperclassman of Habara. Her real name is unknown. She is on bad terms with Yanagi’s Senpai and is shown to always be the first one to start a verbal dispute. It is later revealed that they were classmates during their third year of grade school with Ikushima’s Senpai. It is also hinted that she had something to do with the scar on Karasawa’s chest.