In December 1966, Kuwahara was selected the Japan national team for 1966 Asian Games. At this competition, on December 14, he debuted against Malaysia. In 1968, he was selected Japan for 1968 Summer Olympics in Mexico City. He played 2 matches and Japan won Bronze Medal. In 2018, this team was selected Japan Football Hall of Fame. He played 12 games and scored 5 goals for Japan until 1970.