The fictional setting takes place during the pre-Meiji period of Japan. Yahiko is an orphan from a samurai family who was forced to work as a thief to repay the debt he had presumably owed, as his parents died before they could repay it. When he is rescued by the main character of the story Himura Kenshin, he decides that he will grow up to be just like Kenshin. But because of his strong beliefs, Kenshin will not teach the sword style he had learned. Therefore, Kenshin arranges for Yahiko to be trained by Kamiya Kaoru, the teacher of the . As the series progresses, Yahiko becomes skilled at swordsmanship and faces many opponents.