In June 1956, when Yaegashi was a
Waseda University student, he was selected
Japan national team for
1956 Summer Olympics qualification. At this qualification, on June 3, he debuted against
South Korea. In November, he played at
1956 Summer Olympics in
Melbourne. He also played at
1964 Summer Olympics in Tokyo and
1968 Summer Olympics in
Mexico City. At 1968 Olympics, he played as a captain in first match against
Nigeria, he was replaced for injury in the 78minuts. This match is his last match for Japan. After the match, Although he could not play, he supported Japan team and Japan won bronze medal. In 2018, this team was selected
Japan Football Hall of Fame. He also played at
1958,
1962 and
1966 Asian Games. He played 45 games and scored 11 goals for Japan until 1968. ==Coaching career and post-retirement==