After going through a false wall in Tachibana�s Sweet Shop, Asumu stumbles upon the Oni R&D room where Midori shines some light on Hibiki�s past. Meanwhile, Hibiki believes he�s discovered the secret to defeating the Armored Douji and Hime and begins to time their transformation, but he has to hurry as a Nurikabe is making its way towards the village below the mountain!

Kogure Kounosuke, a strong-willed weapons designer for Takeshi, comes bearing a gift for the Oni who work at the Tachibana Sweet Shop: the Armed Saber. Unfortunately, the weapon is too powerful for a normal Oni and the repercussions for trying to use it is losing the ability to transform. But when a new Douji and Hime appear more powerful than any before, the Oni may have no choice but to risk using it in battle�