When Yahiko first appeared in Rurouni Kenshin, he was a pickpocket who worked for the local Yakuza (kinda like the Japanese Mob). After Kaoru learns that he's being bossed around by the Yakuza, she and Kenshin rescue him. When Yahiko witnesses Kenshin's amazing skill with a sword, he immediatly accepts an invitation to come live with Kenshin and Kaoru, hoping that Kenshin will train him so he can defend his late mother and father's name. Instead of Kenshin training him, Kaoru becomes his Sensei, and although he immediatly dubs her ugly girl and she dubs him the annoying brat, the two end up having a sort of big-sister, little-brother relationship. Although they get into many arguments and fights, which usually end in Kaoru chasing Yahiko around the dojo in anger, each would walk the wire for the other in a minute.

Since Yahiko is still in training, he's not allowed to use a real metal sword yet. But that doesn't mean he's not a good fighter. Provided he doesn't have to take on huge gangs of people, Yahiko is actually pretty good with his dinky li'l wooden sword. And if a sword won't work, he's always willing to give the bad guys a good ol' kick in the goolies. Also, he's got a lot of guts. He's willing to take on guys three times his height to protect his friends, and usually the only thing that stops him from charging headlong into a fight he can't win is a sarcastic comment from Sano, which usually gets Yahiko annoyed enough to glomp onto Sano's back and start biting on his head or something. He also makes a good projectile, as demonstrated by Sano on several occasions ^^.

Since most of the time he's surrounded by adults, Yahiko demands to be treated with equal respect, and absolutely hates being treated like a little kid and being called Yahiko-chan (or Little Yahiko in the english dub). So imagine the look of extreme embarrassment and horror on his face when Tsubume, a girl he has a crush on, calls him Yahiko-chan when they meet for the first time ^^. Needless to say, this provides the group, and Sano in particular, endless ammunition for teasing poor li'l Yahiko.

Yahiko really admires Kenshin, not only because of his amazing skill with a sword, but also because of his downright niceness and how he always comes through whenever they need it. He's part of, as he calls it, Kenshin's Group, and he's dang proud.

I don't know why, but I really, really like Yahiko. The minute I saw him, I just thought, Okay, that little guy with the spikey hair is cool. And for some reason, I've always had a bit of a thing for thieves in stories. Good thieves, I mean. Not evil ones. And besides, his guts impressed me, I mean, not many ten-year-olds have the guts to headbutt Kenshin and start mouthing off at him. Plus, I liked how he was a smartass ten year old.