He was born in Fukuno, Toyama[2] and began judo at the age of 5.[2]
After graduating from Tenri University, Minatoya coached judo at the dojo wichi Anton Geesink managed in Netherlands.[2]
In 1969, Minatoya participated in the World Championships in Mexico City and won a gold medal, defending his world championship.[3]
Minatoya retired in 1972, when he was defeated by Toyokazu Nomura at the All-Japan Selected Judo Championships and missed the participation of the Olympic Games held in Munich.[2]
From 1967 to 2009, he also coached judo at Kanazawa Institute of Technology in Kanazawa, Ishikawa.[4]
- All-Japan Championships (Openweight only) loss
- All-Japan Selected Championships (Lightweight) 1st
- All-Japan Championships (Openweight only) loss
- All-Japan Selected Championships (Lightweight) 3rd