Originally Posted by wikipedia

Peacemaker Kurogane (PEACE MAKER鐵, Peacemaker Kurogane?) is a historical fiction manga and anime series created by mangaka Nanae Chrono (黒乃奈々絵, Kurono Nanae?). The story begins in 19th century Japan before the Meiji Restoration, while the seeds of the revolution are being planted. The story focuses on a boy, Ichimura Tetsunosuke, who joins the Shinsengumi as Hijikata Toshizo's page while seeking to become strong enough to avenge the deaths of his parents.

The series began under the name Shinsengumi Imon Peacemaker (新撰組異聞PEACE MAKER, Shinsengumi Imon Peacemaker?), published by Enix in the magazine Monthly Shonen Gangan, before moving to Mag Garden's Comic Blade in 2001 and picking up the name Peacemaker Kurogane.[1] Kurogane was licensed by ADV Manga, which released three of the five volumes before putting it on hold indefinitely; later, the license lapsed, and Tokyopop acquired it, along with Shinsengumi Imon Peacemaker.[2] The manga was later adapted into a television series by Gonzo Digimation and ran for 24 episodes, which aired on TV Asahi in late 2003 and early 2004. The US license for the anime is held by ADV Films under the title Peacemaker. The anime aired in the United States on Showtime Beyond,[3] alongside Chrono Crusade.

Plot
The story is focused on the main character, Ichimura Tetsunosuke, an energetic, short, and very childlike 15 year old. Sadly, he and his older brother are left to fend for themselves after the vicious murder of their parents. While Tetsunosuke wants to get revenge, his pacifist brother is not so inclined. Interestingly, the story develops when they take refuge working defined jobs in a special police force called the Shinsengumi, where his brother is an accountant and he is a page to one of the groups leaders. While there, Tetsunosuke will attempt to get stronger in order to take the revenge he so desires, but he will be confronted by the hardships that are involved with becoming that powerful.

The anime is also focused on the characters that make up the legendary Shinsengumi and the interaction and conflict they have with one another.