Rurouni Kenshin:

A warrior arose 140 years ago in Kyoto, with the coming of the American "black ships," who helped introduce the progressive age known as Meiji and then vanished. This tale begins in the 11th year of Meiji, in Tokyo. With his killer blade, legend-warrior Hitokiri Battosai once helped close the turbulent Bakumatsu era and slashed open the progressive age known as Meiji. It's now 1878, ten years after the bloody Meiji Revolution that marked the end of the rule of the Shogun and the Samurai in Japan. In Tokyo, where swords have been banned, Kaoru bumps into the wandering Kenshin while looking for the Battosai, who is ruining the name of her fencing school by killing people in the streets using her signature style. Thus begins an extraordinary relationship between Kaoru, a master swordswoman with a heart of gold; Kenshin, a past master who has vowed never to fight again; and the seemingly invincible would-be Battosai.