Baba Shouko is a teacher everyone dislikes because she frequently scolds students and is very strict. A fake Hotline to Hell was created by somebody and it is circulated among students who were just scolded by Baba sensei. Tracing was carried out and they concluded that a student named Ikami Waka created and circulated the fake Hotline to Hell. However, Ikami claims that she did not do it. On the same night, another teacher named Kuriyama Mami calls Ikami and tells her that it was Baba who made the fake Hotline to Hell, blames her for it and told Ikami to come to school. Mami-sensei waits in school for Ikami to come and tried to convince Ikami to access the real Hotline to Hell to send Baba to hell. To her surprise, the one who turned up is Ai. Mami and Ai already knew each other from their pasts. The truth is Mami was the one who created the fake Hotline to Hell and blamed the students for it. It was all because Baba scolded Mami when she was young and she blames Baba for all her problems. Baba comes and types in Mami's name into the real Hotline to Hell, as a punishment for an attempt to use her students as sacrifices. Baba agrees to go to hell as she blamed herself for coaching a teacher like Mami. (thetvdb.com)