Yuzuki accidentally bumps into a first-year student, Katase Ririka, causing her to break a beaker. The two of them report the damage to science teacher, Mio Niiyama, who lets the two off without punishment. Later that night, Mio receives a silent call from an unknown person. The next day, Ririka's grandmother shows up at school and accuses Mio of picking on Ririka despite Yuzuki being at fault and continues to verbally attack her over the phone that night. The situation intensifies as Ririka's grandmother hands out leaflets that defame Mio and announces that she will be keeping Ririka at home until Mio resigns. Mio visits to get Ririka to promise to vouch for her and clear her name, however when Ririka's grandmother returns, Ririka goes against her word and deliberately slanders Mio's intentions, labeling them as harassment. Ririka earnestly explains that because Mio is a teacher and an adult, Mio is able to deal with it herself. Mio types Ririka's name into the Hell Correspondence website, receiving Yamawaro as a doll, and pulls the string sending her to Hell.