Mouryou no Hako: Chuuzenji Atsuko no Jikenbo - Hako no Yurei no Koto
Japanese title: 魍魎の匣～特別編　中禅寺敦子の事件簿「箱の幽霊の事」
Alternative titles: Mouryou no Hako - Hako no Yuurei no Koto, The Case Files of Atsuko Chuzenji: 'The Case of the Spirits in the Boxes', Chuzenji Atsuko no Jikenbo 'Hako no Yuurei no Koto'
Type: Special
Source: Novel
Episodes: 1
Status: Finished Airing
Aired: May 22, 2009
Duration: 16 min
Rating: R - 17+ (violence & profanity)
Studios: Madhouse
Genres: Mystery, Supernatural, Suspense
Themes: Historical

A side story that reveals the investigative notes that Atsuko, the younger sister of the main character Akihiko Chuzenji, wrote about the brutal dismembering incidents in the main story.

(Source: ANN)