"Bakumatsu no Spasibo" is a historical fantasy anime set during the Bakumatsu period in Japan, a time of political upheaval and transition from the Tokugawa shogunate to the Meiji Restoration. The story centers on a group of individuals who become entangled in a conflict involving time travel, alternate realities, and the clash between traditional samurai values and modern ideologies.

The protagonist, Hajime Saitou, is a stoic and skilled swordsman who serves as a captain in the Shinsengumi, a special police force loyal to the shogunate. His life takes an unexpected turn when he encounters a mysterious Russian woman named Anastasia, who claims to be from the future. She possesses a device capable of manipulating time, which attracts the attention of various factions vying for control over its power. Among these factions is the Ishin Shishi, a group of revolutionaries seeking to overthrow the shogunate and restore imperial rule.

As Hajime and Anastasia form an uneasy alliance, they are pursued by both the Shinsengumi and the Ishin Shishi, each with their own motives for obtaining the time-manipulating device. The narrative explores themes of loyalty, honor, and the consequences of altering history, as Hajime grapples with his duty to the shogunate and his growing attachment to Anastasia. Alongside them are other key figures, such as Toshizou Hijikata, the vice-commander of the Shinsengumi, and Ryoma Sakamoto, a prominent Ishin Shishi member, whose actions and ideologies further complicate the unfolding events.

The series blends historical elements with speculative fiction, incorporating real-life figures and events from the Bakumatsu period while introducing fantastical elements like time travel and alternate timelines. The interplay between historical accuracy and creative liberties creates a dynamic narrative that examines the tension between preserving tradition and embracing change. Through its exploration of these themes and its portrayal of the Bakumatsu era, "Bakumatsu no Spasibo" offers a unique perspective on a pivotal moment in Japanese history.