Bakumatsu Kikansetsu Irohanihoheto (幕末機関説 いろはにほへと), usually translated as Intrigue in the Bakumatsu: Irohanihoheto, is an original 2006 TV anime series by studio Sunrise and director Yoshimitsu Oohashi. It is one of the many Japanese titles, focusing on the events between the years of 1853 and 1867 (manga, light novels and anime all pay a huge attention to the period). The Bakumatsu is a rather brief period in the Japanese history, but also one of the most prominent moments in the local history.
Let me tell you just some things that come from then: Shinsengumi, Tokugawa shogunate dusk, Ishin Shishi, the Mieji era.
Read below my review for the anime, which was born for the sole purpose of creating a different telling of the story. More realism than I expected and a number of fun moments, slightly similar to the feeling Peacemaker Kurogane left, but with a much more serious tone.