J-League is a professional soccer league in Japan. Officially established on July 1st, 1991 by Japan Soccer Association. With the J-League, now the Japanese team also participates in the Olympics, the World Cup, and other worldwide matches.

Ken was positioned as a goal keeper in a J-League team before he was betrayed by his so-called best friend. Even after he joined Weiß, he still keeps his love to soccer by playing/teaching soccer with children.

I'm not really familiar with soccer, but when I think J-League and Ken, I think of Nakata Hidetoshi ^^; He was in Bellmare Hiratsuka team before he was picked for the Olympic team at age 19, the youngest so far. So he must be about Ken's age when he joined J-league, probably around 17 years old? Too bad he screwed up at the Sydney 2000 Olympic against USA. Oh, he's not a goalie, by the way.
He's also pretty good looking ^^; He appeared in several TV commercials. The one I saw was a digital camera commercial whose brand I don't remember^^; Maybe it was Canon Ixy digital. Well, anyway so you know now why I think Nakata and Ken are similar... or maybe it's just me ^^;;;;