Representing Japan | Moriyama started 2020 with a fourth place finish at the Junior Orange Bowl International. He competed at the 2019 Junior Invitational and continued 2019 with a third place finish at The Western Junior Championship, as well as a second place finish at the Golf Digest Japan Junior Cup. He took first place at the 2018 FCG International Junior Championship and fourth at the 2018 PING Heather Farr Classic. He also captured the Golf Digest Japan Junior Classic and the Optimist International Junior Championship in 2018. He competed in the 2018 U.S. Junior Amateur Championship after winning the medalist award at the qualifier in Salisbury, North Carolina. Born in Japan, Moriyama has committed to attend and play for the University of Oregon in 2020.