 Complete the following phrase:  Yamaguchi was born in Sakawa, Kochi on April 17, 1978. He joined JEF United Ichihara later JEF United Chiba from youth team in 1996. He debuted on March 20, when he was 17 year and 354 days old. It was the youngest player to play for J1 League until Yuki Abe made new record in 1998. He became a regular player as center back from 1997. He moved to Gamba Osaka in 2001. The club won the champions 2005 J1 League, 2007 J.League Cup, 2008 and 2009 Emperors Cup. He was also elected Best XI for 3 years in a row 2006-2008. In Asia, in 2008, the club won the champions AFC Champions League and the 3rd place 