"Chiruran Nibun no Ichi" is a historical comedy manga set during the Bakumatsu period in Japan, focusing on the Shinsengumi, a special police force loyal to the Tokugawa shogunate. The series blends historical events with exaggerated humor and anachronistic elements, offering a lighthearted take on the lives and exploits of the Shinsengumi members.

The narrative revolves around the daily lives and interactions of the Shinsengumi, particularly their leaders and key figures, such as Isami Kondo, Toshizo Hijikata, and Soji Okita. While the manga incorporates real historical events, such as the group's involvement in political conflicts and their efforts to maintain order in Kyoto, it often prioritizes comedic and absurd situations over strict historical accuracy. The characters are portrayed with exaggerated personalities, with Kondo depicted as a kind but bumbling leader, Hijikata as a strict and hot-tempered vice-commander, and Okita as a carefree yet deadly swordsman.

The manga frequently parodies the serious and often tragic nature of the Shinsengumi's historical legacy, reimagining their struggles and rivalries with rival factions, such as the Ishin Shishi, in a humorous and over-the-top manner. Despite its comedic tone, the series occasionally touches on the camaraderie and loyalty among the Shinsengumi members, highlighting their bond as they navigate the chaotic final years of the Tokugawa shogunate.

"Chiruran Nibun no Ichi" also features a wide array of supporting characters, including other Shinsengumi members like Hajime Saito and Shinpachi Nagakura, as well as historical figures like Ryoma Sakamoto. The interactions between these characters often drive the humor, with the manga frequently breaking the fourth wall and incorporating modern references for comedic effect. The series balances its comedic elements with occasional moments of action and drama, providing a multifaceted portrayal of the Shinsengumi's legacy.

Overall, "Chiruran Nibun no Ichi" offers a unique and entertaining reinterpretation of the Shinsengumi's history, blending historical facts with absurd humor and anachronistic storytelling to create a distinctive narrative that appeals to fans of both comedy and historical fiction.