"Katsugeki: Touken Ranbu" is a historical fantasy anime set in Japan's late Edo period, blending action, supernatural elements, and historical revisionism. The narrative centers on a group of anthropomorphized swords, known as Touken Danshi, who are tasked with protecting history from the Time Retrograde Army, a mysterious force seeking to alter the past. These swords, once wielded by historical figures, have been brought to life by the Saniwa, a sage who commands them to preserve the timeline.

The story primarily follows two units of Touken Danshi: the First Unit, led by Izuminokami Kanesada, and the Second Unit, led by Yamanbagiri Kunihiro. Izuminokami, a passionate and headstrong sword, serves as the protagonist, driven by a desire to prove his worth and protect history. His partner, Horikawa Kunihiro, is a loyal and composed counterpart who balances Izuminokami's fiery demeanor. Yamanbagiri Kunihiro, the leader of the Second Unit, struggles with feelings of inadequacy due to being a replica of an original sword, yet his determination to protect history remains unwavering. Other key characters include Mutsunokami Yoshiyuki, a cheerful and optimistic sword with ties to the Bakumatsu period, and Tsurumaru Kuninaga, a mysterious and playful figure with a penchant for surprises.

The plot unfolds as the Touken Danshi are dispatched to various historical battlefields and pivotal moments in Japanese history, such as the burning of Kyoto and the Bakumatsu period. Their mission is to confront the Time Retrograde Army, which manifests as corrupted spirits and historical figures manipulated to disrupt the timeline. The battles are intense and often carry emotional weight, as the swords confront their own histories and the legacies of their former wielders. Themes of identity, duty, and the weight of history are explored as the characters grapple with their roles as both weapons and protectors of the past.

The anime balances action-packed sequences with moments of introspection, delving into the personal struggles and relationships of the Touken Danshi. The narrative also incorporates historical accuracy in its settings and events, providing a backdrop that enriches the story's context. As the series progresses, the stakes escalate, with the Time Retrograde Army's motives becoming increasingly complex and the Touken Danshi facing greater challenges to preserve the integrity of history. The story concludes with a resolution that underscores the importance of safeguarding the past while leaving room for the characters' continued growth and missions.