After learning of possible Gedoushu activity on an island, the Shinkengers travel to investigate. After splitting up into three groups, Takeru and Mako and Genta and Chiaki are ambushed by villagers driven insane. Ryunosuke and Kotoha encounter a young boy who tells them of an ash causing an illness amongst the villagers, making them paranoid and blood-thirsty. When the two go to warn the others, they are ambushed by Dayu and knocked out. Elsewhere, Akumaro ambushes Genta and Chiaki, placing them under the influence of the ash that he has created, and Juzo attacks Shinken Red and Pink, noting that Takeru has become weaker upon valuing his life over that of fighting. This distracts him and allows Juzo to injure him until Mako takes him out of the battle and into safety. Still angered, he runs off to fight Juzo, again, with Mako in tow. They arrive at a mountain guarded by Juzo and Dayu that is producing the ash infecting the village. While Mako fights Dayu as Shinken Pink, Takeru transforms into Super Shinken Red to fight Juzo and free the island from the ash's influence. After destroying the source of the ash and breaking Akumaro's hold on the island, Akumaro takes Juzo and Dayu away, leaving a Kirigami and a pair of ?nosakamata to keep the Shinkengers at bay. The group forms Daikai-Shinkenoh to fight the monsters and to destroy the ?nosakamata, eventually needing to use Samuraihaoh to destroy the Kirigami. Having freed the island, the Shinkengers head back home, with Juzo's words still burning in Takeru's mind as Mako keeps a worried eye on her lord.