On August 6, 1995, Nanami debuted and scored a goal for Japan against Costa Rica. From 1996, he became a central player and wore the number 10 shirt. In 1996, he played all matches for Japan included 1996 Asian Cup. At 1998 World Cup qualification in 1997, Japan won the qualify for 1998 World Cup first time Japan's history. In 1998, he played all matches included World Cup. He also played at 1999 Copa América and 2000 Asian Cup. At 2000 Asian Cup, he played full time in all matches and scored 3 goals. Japan won the champions and he was selected MVP Awards. After he hurts his knees in 2001, he did not play for Japan. He played 67 games and scored 9 goals for Japan until 2001.