S3·E20 Hell Doctor vs. Hell Girl

An old man named Mizuragi Shōgo types Tsugumi's name into the Hell Correspondence. Each sensing the request, Yuzuki, Ai, and Tsugumi go to his mansion. Shogo explains that he gained interest in Hell after his mother used Ai's services to send his father to Hell. After years of research, he yearned to meet Ai and so had an artificial grudge against Tsugumi planted in his mind through hypnosis in order to feel enough hatred to meet her. The others all protest, as Tsugumi has done no wrong, but luckily, just before Shogo can pull the string to send her to Hell, he is instead sent to Hell by his assistant due to how Shogo took in many orphaned children only to treat them cruelly and try to send them to Hell for his research.