Roy Nagatoshi is a professional bonsai instructor and owner and operator of a bonsai nursery, Fuji Bonsai Nursery, in Sylmar (suburb of Los Angeles), California.

Roy's first encounter with bonsai was in 1959, working side by side with his father, Shigeru, on various bonsai. His background knowledge, skill and respect of the art of bonsai come from his mentors, his father, Shigeru, and John Naka. Fluent in the Japanese language, Roy's never-ending enrichment in knowledge continues to come from past and contemporary bonsai literature in both Japanese and English. Roy holds a Bachelor of Science degree in Ornamental Horticulture from Cal-Poly University in Pomona, California. Roy also holds a lifetime teaching credential for the community colleges in the State of California.

Ever since 1976, when he first gave his bonsai lecture demonstration to a local club, Roy has been a guest bonsai artist at numerous bonsai organizations and major bonsai conferences throughout the United States and the world.

Roy is a proud member of California Bonsai Society. He served eight years as the President of the Society and also chaired two anniversary conventions of the Society.