[SUB] Sumireko and Adashino work and chat together in the quiet of the bookshop where they're employed. Their manager appears and gives Sumireko a strange book of unknown origins. Just after midnight, she casually picks it up to read it, and then.

The curse of Tsukuyomi's Water of Youth hasn't finished with Sumireko yet. Meanwhile, Adashino's younger sister, Oto, picks up on the presence of a Curiosity at the school she attends. Sumireko poses as Oto's friend in order to infiltrate the school.

Sumireko and her coworker, Ren, set out to investigate urban legends, black magic and ghost stories.

Adashino cries in the deserted Midori Bookshop once more; Sumireko intends to spend her day off writing; as she's admiring the sakura outside her window, she gets a text from Adashino asking her to look after Oto for two or three days.

Sumireko looks after Oto while Adashino is away; she and Oto run into Uname and spend the evening with her; but their peace is short-lived as the shadow of a new Curiosity draws near.

Shizuku is looking for Tomoko, who disappeared on a rainy night a year ago; based on Tomoko's final video call, Adashino has a guess about the Curiosity, but he has a few concerns; Oto wants to help Shizuku, so she begins her own search.