A supernatural system allows people to take revenge by having other people sent to Hell via the services of a mysterious entity and her assistants who implement this system. Revenge, injustice, hatred, and the nature of human emotions are common themes throughout the series.
- Year: 2017
- Country: Japan
- Genre: Animation, Drama, Mystery, Sci-Fi & Fantasy
- Studio: Tokyo MX, Kids Station, Gunma TV, BS11, ANIMAX
- Keyword: detective, supernatural, hell, bullying, revenge, tragedy, curse, death, dark fantasy, school life, angst, seinen, anime, comeuppance
- Cast: Masaya Matsukaze, Mamiko Noto, Takayuki Sugo, Takako Honda, Kanako Sakai, Hekiru Shiina