Samurai X: Trust & Betrayal (1999)
In Meiji era Japan, Kenshin Himura has been trained in the deadliest of sword arts. When the House he was hired by is defeated and forced into hiding, Kenshin must pretend to be the husband of Tomoe. The only catch is, Kenshin killed her fiance, and she is now secretly spying on him. While in hiding, Kenshin and Tomoe grow to love each other, and Kenshin comes to terms with who he is. This is the backstory to the Rurouni Kenshin manga and to a lesser extent, the television series based off of the manga.