The Medium's Birthplace

Mikan and Nekoyashiki return to Mikan's family, and their extended absence causes Itsuki to inquire as to their status. Suzuka Katsuragi, the head of the family and Mikan's grandmother, refuses to return Mikan to Astral, and reveals that Nekoyashiki has been missing. Itsuki and Honami travel to the Katsuragi estate, where Suzuka offers to consider returning Mikan if Astral eliminates an oni on the mountain. Along with their guide, Tatsumi Shitō, they travel up the mountain to an area where dozens of oni attack them. The three are ultimately engulfed by the magical pollution present, and Itsuki awakens to find Nekoyashiki with Mikan's missing sister, Kaori Katsuragi. Nekoyashiki and Kaori explain that the ritual the Katsuragi are performing places the oni of the mountain into the next family heir, killing them, and Suzuka wishes this to be done to Mikan. Nekoyashiki claims he kidnapped Kaori to prevent the ritual from occurring, but due to a trace placed on Itsuki revealing Kaori's location, Suzuka begins the ritual.