AC Nagano Parceiro
Yokoyama was born in Tama, Tokyo, on 13 August 1993. After graduating from high school, they joined Okayama Yunogo Belle in 2012. In 2014, they moved to L.League Division 2 club AC Nagano Parceiro. They became top scorer in 2014 and 2015. The club was also promoted to Division 1 from 2016. In 2016 season, they were selected Best Eleven. In July 2017, they moved to German Bundesliga club Frankfurt. In July 2018, Yokoyama returned to AC Nagano Parceiro. In December 2019, they signed with the Washington Spirit.