In January 1995, Okano was selected by the Japan national team for the 1995 King Fahd Cup, but he did not play in the match. On September 20, he debuted for the Japan national team against Paraguay. In 1996, he played at the 1996 Asian Cup. During 1998 World Cup qualification, in the final qualifier match for the 1998 World Cup against Iran, he scored the golden goal that took Japan to their first ever World Cup finals. At the 1998 World Cup, he played 29 minutes as a substitute against Croatia. He also played at the 1999 Copa América. This competition was his last game for Japan. He played 25 games and scored 2 goals for Japan until 1999.