Watch Katsugeki Touken Ranbu Online

In 1863, Izuminokami Kanesada and his partner, Horikawa Kunihiro, arrive in the streets of Edo from the future to investigate their master's reports of an upcoming enemy invasion. As humanoid manifestations of the famous Toshizou Hijikata's swords, they have been tasked with protecting history from the Retrograde Army that seeks to alter it. Soon enlisting the help of other sword warriors, they continuously battle the mysterious army throughout the Bakumatsu period. However, their journey will not be an easy one. Fraught with blood and betrayal in the chaotic era closest to their hearts, the duo will be forced to make difficult decisions with everything they care about on the line. [Written by MAL Rewrite]

Our heroine has been kidnapped and her two somewhat ditzy friends decided to save her in a war machine they found in her house. Unfortunately they have little idea of how it works so let the random destruction begin.