In 2000, Inamoto played at 2000 Asian Cup. He played four matches while Japan won the championship. In 2001, he also played at 2001 Confederations Cup. He played four matches and Japan came second place. In 2002, he was selected Japan for 2002 World Cup. He played all four matches and scored two goals against Belgium at first match and Russia at second match. Japan qualified to the knockout stage first time in Japan's history.