In 2010, Yokoyama was selected the Japan U-17 national team for 2010 U-17 World Cup. She played 6 games and scored 6 goals, and Japan won 2nd place. She received one of the ten 2010 FIFA Puskás Award nominations for her 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 she was also a member of the Japan U-20 national team for 2012 U-20 World Cup which Japan won the 3rd place. In March 2015, she was selected the Japan national team for 2015 Algarve Cup. At this competition, on March 6, she debuted and scored a goal against Portugal. In 2018, she played at 2018 Asian Cup. She scored 4 goals include 2 goals at semifinal and a goal at final, and Japan won the championship.