Seven episodes from the Japanese anime based on the light novel from Nisio Isin's 'Monogatari' series. When transfer student Ougi Oshino (voice of Kaori Mizuhashi) arrives at Naoetsu Private High she immediately seeks out third year student Koyomi Araragi (Hiroshi Kamiya) in the hope that he can help solve the mystery behind a strange discovery she has made. After studying plans of the school, Ougi notices a secret classroom which is not listed on the blueprints. However, when Koyomi joins her to investigate, he soon realises the room is linked to a number of troubling memories from his past. In this instalment, Koyomi is sent to Avici, the lowest level of Hell. The episodes are: 'Mayoi Hell: Part One', 'Mayoi Hell: Part Two', 'Hitagi Rendezvous: Part One', 'Hitagi Rendezvous: Part Two', 'Ougi Dark: Part One', 'Ougi Dark: Part Two' and 'Ougi Dark: Part Three'.