About Kido Jyou
In Digimon Adventure, Jyou is 12, and in 02, he's 15. He's the oldest of the Digi-Destined, and fell in with the original 7 at the begining of Digimon Adventure. I like to consider Jyou the nurse of the group, which is very needed with this group. Okay-so he's a little afraid of the Digiworld at first...but who wouldn't be?
In 02, Jyou is in high-school, (And looks...bishonen-y, I must say!) and is too old to be a digi-destined, along with the others, excluding Takeru and Hikari.
He really doesn't have a starring role in the movies, but he makes brief apperences.
Jyou's digimon and his stages are Bukamon, Gomamon, Ikkakumon, and Zudomon. He has yet to digivolve to the mega-level. Gomamon and Jyou don't really get along at the begining of the series, but they call a peace further along.
Jyou's family (as we know of in Digimon Adventure) consists of his brother (Shin) and his father. Jyou has a fear of defying his father, who is pressuring Jyou to become a doctor. Shin is telling Jyou to follow his own path, but Jyou hasn't done it yet.
Why I think Jyou is good for Koushiro: Jyou is a good friend and someone you can trust. He didn't think about himself for an instant when he pushed Koushiro away from Piedmon, and Koushiro needs someone who can take care of him.