Yutaro is a young boy that inherited a HUGE fortune from his parents. His parents had died when he was younger. He appears when Dr. Genzai's sister (she looks just like his brother) is working for Yutaro.
Yutaro lived in a wealthy mansion on a hill, who was practically served and waited on everyday. He wanted to learn swordsmanship since his father was deemed as an excellent fighter. He sees Kenshin with a sword and demands lessons from him. But Kenshin refuses, and Yutaro flies off the handle and says negative things about him. As time went by he found a man, Rijuta, that uses a powerful sword. Yutaro asks for Rijuta to teach him the sword techniques.
Later, Rijuta was planning an attack on the Meiji Government and asked the Battousai for help. When Kenshin said, "No", Rijuta ordered his followers to "Kill Him!" Well, Yutaro was spying (aye vey....talk about eavesdropping) and while Kenshin and the other men were fighting, one of Rijuta's men charged at Kenshin and Kenshin got the weapon out of the mans hand, which hit Yutaro in the head, and he lost his balance (they were at a very steep cliff, with the ocean below them). Yutaro fell in and Kenshin was a in a fiery rage, defeated the men, and dove into the sea to rescue Yutaro.
The next morning, Kaoru wonders why Kenshin hasn't returned and Megumi suddenly sees Kenshin with Yutaro in his arms, unconscious, with both of them soaking wet. Yutaro remembers in a dream that Kenshin saved him. He thanks Kenshin (after he recovered) but still thinks that Rijuta is a good man (because Kenshin, Sano, Kao, and Yahiko said, "Rijuta is very dangerous! Stay away from him!").
At the mansion, Rijuta is planning an attack on the police that know he is planning to overthrow the government. Yutaro hears the news and rushes over. Kenshin learns of this and follows Yutaro to the woods, where Rijuta is actually at. Rijuta said he'd defeat Kenshin, but Yutaro tried to stop him. Well, Kao, Yahiko and Sano told him he wouldn't listen anyways, and Yutaro said that they're wrong. Well, THEY were right. Rijuta was fed up with this nonsense and detached Yutaro's veins and muscles in his right arm. Yutaro was in shock. Rijuta laughed at him and said he'll die right now. Kenshin got up with those RAGING eyes and said he'd defeat Rijuta for manipulating an innocent boy's heart. Yutaro passes out because of the pain and his humiliation. In the end, Kenshin defeats Rijuta. Megumi says Yutaro probably can't learn swordsmanship from this incident. Yutaro then decides to go off and live in Germany with his uncle.
He appears later in Part 3, with the Black Knights who are after the Divine Elixir.
Overall, Yutaro seems to be spoiled quite a bit, but, he does show care for people and sometimes he doesn't think of his own life in a life or death situation.
Source : www.absoluteanime.com