Chukyo University
Miyaichi was born into a sporting family. His brother, Tsuyoshi, was also a football player; and his father, Tatsuya Nomoura, was a basketball player who played for and later managed the Toyota Motors basketball club. Miyaichi started playing football in his elementary school years at Sylphid F.C. in Nagoya. He entered Chukyo University Chukyo High School and played for the school football club. In the 2010 season, the team advanced to the All Japan High School Soccer Tournament but were defeated in the first round in a match televised across Japan.