Ep. 22: Sealed darkness opens, revealing a red sky and a suspected spy among the group.

22

Shirogane’s sealed barriers rupture, triggering a red-sky phenomenon and a surge of Kokuchi attacks. Kou is overwhelmed by the enemy numbers while Haruka suspects a traitor within their ranks. Akira, Kengo, and Aya flee to Kou-nii during the school assault. Shirogane arrives with a smile, but Haruka accuses him of being the spy. Ruru intervenes, claiming the plan was exposed, though Shirogane denies this. He takes Akira to an abandoned building for a close, intimate conversation. Kou arrives and dives from a height with Shirogane, ultimately sacrificing himself to kill Shirogane.