Yahiko is one of the two last members of the Kamiya Dojo. Karou meets Yahiko when he attempts to steal Kenshin's money. Yahiko gets caught and tries to run away. They find him, and Kaoru and Yahiko starts yelling at each other. Kenshin talks to him and asks that how he became a pickpocket. Kenshin does not believe that he would willingly do such a thing because yahiko has so much pride and such a big ego. Yahiko runs away and Kenshin and Kaoru go to the Akabeko. Kenshin and Kaoru find out that Yahiko was forced to steal because of a gang. The gang lies to Yahiko, telling him that they payed for a medical bill for his mother, but infact had done no such thing.

Kaoru gets really pissed when she hears this. She rushes to the gangs hideout and tries to save Yahiko. Kaoru challenges them to a game of dice. Kaoru wins, with the help of Yahiko.

Although Yahiko starts out skeptical at the Kamiya Kasshinryu's power, he soon learns how powerful this technique is. Yahiko slowly gets stronger. He soon is capable of defeating a useless thug and then towards the end of the anime defeats one of Shishio's Ten Swords.

He uses a shinai [a bamboo sword]. Currently in the process of learning the Kamiya Kasshinryu from Kaoru. He occasionally imitates Kenshin's moves.