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�

After losing the Armed Saber to the Super Douji and Hime, Hibiki and Todoroki lose the ability to transform. They find out that they will regain the ability to transform in one month, but that is too long with a Makamou running amok. Kogure suggests that the two Oni undergo a special training, under his guidance, to regain their powers.