In 2010, Yokoyama was selected Japan U-17 national team for 2010 U-17 World Cup. They played 6 games and scored 6 goals, and Japan won 2nd place. They received one of the ten 2010 FIFA Puskás Awards nominations for their winning goal in the semifinals against North Korea, which made the headlines and was compared to Diego Maradona's second goal against England in the 1986 World Cup. In 2012 they were also a member of Japan U-20 national team for 2012 U-20 World Cup which Japan won 3rd place. In March 2015, they were selected Japan national team for 2015 Algarve Cup. At this competition, on 6 March, they debuted and scored a goal against Portugal. In 2018, they played at 2018 Asian Cup. They scored 4 goals include 2 goals at semifinal and a goal at final, and Japan won the championship.