Yokoyama had its first international success at the 2011 Junior World Championships in Courmayeur . There he won the silver medal with the relay. At the Junior World Championships 2013 in Warsaw he won the bronze medal with the relay. He made his debut in the World Cup at the beginning of the 2014/15 season in Salt Lake City , which he finished in eighth place over 1500 m. At the Winter Universiade 2015 in Granada he finished fourth in the relay and won 15th place in the all- around at the 2015 World Championships in Moscow . In February 2017 he took in the Asia Play Winter inSapporo the bronze medal with the relay. In the 2017/18 season he achieved his first podium finish in the World Cup with third place in the relay in Budapest . At the season highlight, the Winter Olympics in Pyeongchang in February 2018, he came in 23rd place over 1500 m and in seventh place with the relay. The following month he won the bronze medal with the relay at the World Championships in Montreal. In the 2018/19 season he finished second with the relay in Dresden and Turin .
Personal bests
500 m 41.246 sec. (installed on November 16, 2014 in Montreal)
1000 m 1: 24.118 min. (installed on November 4, 2018 in Calgary)
1500 m 2: 11.392 min. (installed on November 9, 2018 in Salt Lake City)