In July 2012, Tokunaga was selected Japan U-23 national team as over aged player for 2012 Summer Olympics. He played 5 matches as left side back and Japan reached the semi-finals where they lost to eventual gold medalists, Mexico, and then lost the bronze medal play-off match to South Korea. In July 2013, Tokunaga was selected Japan under manager Alberto Zaccheroni for 2013 East Asian Cup for the first time in 3 years. At the tournament, he played 2 matches as left side back and Japan won the champions. This tournament is his last game for Japan. He played 9 games for Japan until 2013.