In July 1996, Kawaguchi was selected the Japan U-23 national team for 1996 Summer Olympics and he played in all 3 matches. In first match against Brazil and Japan won Brazil (1-0). It was known as "Miracle of Miami" () in Japan. On February 13, 1997, he debuted for the Japan national team against Sweden. After the debut, he became a regular goalkeeper soon. In 1998, he was selected the Japan at 1998 World Cup and played all 3 matches. After the 1998 World Cup, he battles with Seigo Narazaki for the position for a long time. He played at 2000 Asian Cup and 2001 Confederations Cup. Japan won the champions at 2000 Asian Cup and the 2nd place at 2001 Confederations Cup. From 2002, he could not play in the match behind Narazaki. At 2004 Asian Cup in summer 2004, he played all matches instead Narazaki who injured. Japan won the champions and Kawaguchi became a regular goalkeeper again after the Asian Cup. He also played at 2005 Confederations Cup and 2006 World Cup. After the 2006 World Cup, he named a captain by new manager Ivica Osim. From 2008, his opportunity to play decreased for injury. He played 116 games for Japan until 2008. Although he was not selected the Japan from 2009, he was selected the Japan as reserve goalkeeper for 2010 World Cup by manager Takeshi Okada.