It is revealed that after the civil war in myCast: Edo part 2, Miyahira Katashi and some of his men survived and is now plotting to overthrow the bakufu in Edo myCast once again and destroy the "rotten" world at any cost by forming an extremist group known as the Kiheitai. At the same time, a special police force consisted of elite swordsmen was formed by the bakufu in order to maintain the security in the Edo myCast. Some members of the group are the ones that survived in the previous war while some are new generation samurais and are the heir to the samurais that sacrifice themselves in the battlefield during the previous war and also some that survives but retires after that. They fought on the side of the shogunate against the newly found extremist group. But, it's not just them, an independent group with similar goal led by Shiroyasha are also joining them in the battle, on the side of the villains, there are a group of deadly assassins and strange creatures known as demons joining them as well. Shiroyasha will finally face against his worthy opponent once again. Who will fall and who will stand still ?
