There is a treasure from ancient times called Taiichinowa, which can manipulate space-time. Whoever possesses this treasure has the power to manipulate large parts of history for their own benefit, and it seems that’s exactly what the Taihaku Empire intends to do.
The Taihaku Empire is mass producing deadly robot beasts that are sowing chaos and death by decimating villages and regions with little resistance. Surrounding regions are just the beginning, too; they aspire to become the conquerors of the entire world.
Sisters In and Nei are well aware of the trouble their region is in. After all, three years prior, their own village was attacked by the Taihaku Empire, with both of their parents getting killed in the process. With no chance at revenge, the sisters go from village to village, making their livelihoods as traveling entertainers… Until one day, In acquires a mysterious document called Tensho.
From Tensho, a legendary sword called Kenenken is gifted, and just in time too, because they’ve come across another unfortunate village that’s about to meet its ends thanks to the Taihaku Empire. Deciding that enough is enough, In takes up arms with the sword…and surprisingly, has enough power to repel the army’s attack.
After discovering that their childhood friend Shou was whisked away to become a slave to the Taihaku Empire, In and Nei join forces with a growing rebel army that’s doing all they can to stop the madness. Some of the members of the rebel army even have their own strange abilities and powers.
One by one, they begin to win battles against the Taihaku Empire and their strange machines, but even with the same goal in mind, disputes within the rebel army slow their own progression towards freedom. Not only that, but In and Nei are fated to meet Shou yet again, except this time as mutual enemies…and that meeting will shift the course of the battle, and history, in a monumental way.