In exchange for her help, Gaen requests three tasks from Koyomi, all being connected to Suruga Kanbaru, formerly known as Suruga Gaen. Izuko reveals herself as her aunt, but she doesn't want to be introduced to her as one, because she cares for Suruga's feelings. When Koyomi accepts, she shows the darkness' true motive - it is after apparitions not behaving like they should, and this time it isn't after Shinobu, but Mayoi. She exposes Mayoi as a "ghost of a ghost", who should have passed on on Mother's Day, when she finally found her way home; she also stopped leading people astray, neglecting her duty as a lost cow. After Gaen leaves, Mayoi realizes she has to pass on, rather than be eaten by the darkness, and thus she bids Koyomi farewell by kissing him and telling that she loved him. Four months later, Koyomi tells the story of the incident to only one person - Ougi Oshino. On his way home, he realizes he never told Mayoi one thing he should have said - goodbye.
『くらやみ』から逃れ、潜んでいた山から下山した暦たち。
山中の村に立ち寄ったところ臥煙伊豆湖に出会い、『くらやみ』について説明を受ける。
가엔 이즈코가 들려준 어둠의 진상은 가히 충격적인 것이었다. 괴이가 아닌 법칙. 그것은 괴이로서의 역할을 못하는 괴이를 지워버리는 법칙. 그 목표는 400년 전에는 신 행세를 한 시노부였으며, 이번에는 본분을 잃은...
En échange de son aide, Gaen demande trois requêtes à Koyomi, toutes connectées à Suruga Kanbaru, anciennement connue sous le nom de Suruga Gaen. Izuko révèle être sa tante mais ne veut pas être présentée comme telle auprès d'elle afin de ne pas bouleverser ses sentiments. Quand Koyomi accepte, elle démontre les véritables motivations des ténèbres, une manifestation d'un ordre naturel, des moyens de détruire les singularités qui ne se comportent pas comme elles le devraient, dans ce cas précis, il ne s'agit pas de Shinobu, mais de Mayoi.
Non sapendo cosa fare, i tre decidono di scendere dalla montagna per contattare la senpai di Yozuru ed esperta specialista, Izuko Gaen, che solitamente sa tutto. Giunti a un villaggio, bussano a una casa per chiedere di utilizzare il telefono, ma ad aprire loro la porta è proprio Izuko...
