Peace Maker Kurogane - Chrono, Nanae

The sword-slashing sequel to Peace Maker is here! Three months have passed since the Ikedaya Incident that crushed the anti-shogunate rebellion—and propelled the Shinsengumi, Kyoto's now-official police, into history as Kyoto's premium peacekeeping force. But there is no rest for the peaceful: An unexpected threat to the Shinsengumi arises, and it's going to take more than mere swords to defeat this new terror on the horizon.

(Source: Tokyopop)

Peace Maker Kurogane had three volumes released in English by ADV Manga from October 4, 2004 to March 22, 2005 before the license was dropped and the publisher went defunct. Tokyopop picked up the series, republishing the previous volumes and releasing volumes 4 and 5 from March 10, 2009 to October 18, 2010.