Owarimonogatari Second Season

Koyomi Araragi wakes to find Mayoi Hachikuji standing before him in a place she identifies as Avichi, the lowest level of hell. Mayoi appears to know both the timing of Koyomi's death and exactly where he would arrive, knowledge he finds immediately suspicious. She explains that she has come to collect him at someone else's request. The encounter begins a new set of supernatural mysteries that includes the Mayoi Hell, Hitagi Rendezvous, and Ougi Dark arcs.