In January 1995, Yamagugchi was selected Japan national team for 1995 King Fahd Cup. At this competition, on January 6, he debuted against Nigeria. After debut, he became a regular player and he played most matches for Japan until 1998 World Cup. In 1996, he played full time in all matches at 1996 Asian Cup. At 1998 World Cup qualification in 1997, he played all matches and Japan won the qualify for 1998 World Cup first time Japan's history. At 1998 World Cup, he played full time in all 3 matches. This World Cup was his last game for Japan. He played 58 games and scored 4 goals for Japan until 1998.