Kenshin's past is a rather painful topic. He was born of the name Shinta and his parents died of cholera. He was sold into slavery where three young women took care of him. But bandits killed everyone in the band but Shinta until a large man by the name of Hiko Sejuro, master of the Hiten Mitsurugi style, killed the bandits. He found Shinta and took him in, giving him the name Kenshin (which means "Heart of Sword")

 

Kenshin was raised and trained by Sejuro in the Hiten Mitsurugi art of swordsmanship. When he became a young teenager, Kenshin left him and became an assassin. By the age of 18, Kenshin had killed countless people and had earned the name "Hitokiri Battousai" (meaning "Man-slayer", methinks").

 

One of his victims was the fiancé of Yukishiro Tomoe. Her fiancé, Kiyosato Akira, is the man who gave Kenshin the first part of his distinctive cross-shaped scar, and it constantly bled. She became furious and joined the Ishinshishi as a spy so she could take revenge on Kenny. Angsty chicky, neh? The two met and Kenshin fell in love. She, too, began to feel for him and they secretly marry, living for a short time in peace. But the Ishinshishi hadn't forgotten their goal and attempted to kill Kenshin. Tomoe tried to stop the fight but is accidentally killed by Kenshin. As she lay dying, she took a dagger and finished the scar, which never bled since. Kenshin swore never to take a life again.

 

Ten years later, Kenshin's become a rurouni (a wandering samurai but with no master. Kinda like a Japanese hobo.). He's usually peaceful, polite, and pretty quiet. But piss him off and he becomes...

This would be Kenshin's Mr. Hyde to his Dr. Jekyl. His eyes change from lavender to yellow and his face seems to go rather pointy. 0-0' Kenshin constantly has to fight off this persona during battle because this is, well, Psycho Ken, and Kenshin took a vow never to kill. Pretty creepy, neh?