In the manga and anime, Rurouni Kenshin, the protagonist Himura Kenshin was an assassin for the Choshuu Isshin Shishi, whose objective was to overthrow the shogunate, who had ruled Japan for 300 years. Using the ancient sword school, Hiten Mitsurugi Ryu, Kenshin killed from the shadows with his lightning fast battoujutsu, or sword drawing technique. Because he was a master of sword drawing, he was nick named Battousai.
So Battousai killed, never giving a thought about the lives he took. To him, they were obstacles to the new era, to be cut down without mercy. At the tender age of 15, he had already killed over 100 men.
After a series of tragic events, Himura Battousai threw down his daisho and took up the Sakabatou, a katana with a the blade on the inside and the dull edge on the outside. He wandered Japan for ten years after the Bakumatsu no Douran ended until he ended up in Tokyo.
There he was accosted by a young woman with blue eyes and a hard bokken. Kenshin helped the young woman, Kamiya Kaoru to fight some thugs who were trying to force her to sell her kenjutsu dojo. Kaoru was grateful and asked Kenshin to stay at the dojo with her.
Happy at the idea of having a home for the first time in over a decade, Kenshin took up her offer. So began the great adventure.