The Seven Mysteries Investigative Team Forms!

Rumours of the Academy's Seven Mysteries ripple through the classroom after Sosha recounts a spooky campus legend. While Eho shrinks back, Himawari grows curious enough to propose a nighttime expedition to every haunted spot on the list. Kae signs on for the outing, which leaves Kawaki grumbling about being roped into it. Shino grants the students permission to linger past hours, on the condition that they scrub the building as a training exercise.

Once darkness falls and the group slips inside, Kae quietly pulls Kawaki aside and admits the whole legend is a fabrication. To keep her classmates' sense of wonder alive, she arranged for Batora to stage each phenomenon, and she talks Kawaki into lending a hand. Away from the others, Batora explains why she cares so deeply: raised as an heir, she never had the chance to simply be a kid or roughhouse with friends, and these pranks let her reclaim a bit of that lost childhood.

The staged hauntings unfold one after another. Anatomical models seem to lurch to life, kunai whistle past in the training hall, and red-tinted water sprays out of a bathroom courtesy of Batora's Water Release. In the courtyard, a Third Hokage statue appears to stride on its own, until Himawari activates her Byakugan and catches Kawaki and Batora hauling it. Rather than expose them, she lets the pair slip off and pretends she simply lost the trail.

Everything shifts when a truly unexplained shrouded shape looms over the remaining children, since Batora was still busy tidying the supply room and could not have been behind it. Eho and Yuina faint dead away, Kawaki lunges at the intruder, and it slips his grasp and bolts. Determined to unmask it, Kae gives chase with Kawaki and Batora, while the faked mysteries seem to spring up around them for real. The trail ends at the faculty room, where they find Shino glowing head to toe, coated in luminous residue from the insects he uses to clean.

Episode 264 belongs to the Kawaki and Himawari Academy Arc, first airing in Japan on 28 August 2022 and reaching English audiences on 26 March 2024. It runs under the opening Kirarirari and the ending Biboroku.

The installment pays off a running joke that the legend actually holds only six documented mysteries, with the true seventh left deliberately blank. By morning, students retell the tale of the glowing phantom in the faculty room, and that sighting of Shino becomes the missing seventh mystery, which quietly pleases him. Himawari confesses she had believed the whole affair at first and was glad Kae enjoyed herself, drawing a rare word of thanks from Kawaki.