Naomi Sagara (Japanese: ???? born 1945) is the stage name of Yamaguchi Nahoko, an award-winning Japanese popular singer who was prolific between 1967 and 1980.
She won numerous awards as a singer and composer, branching into acting.
After a surgery to remove polyps on her vocal chords in 1985, she became a business woman.
Since 1993, she has worked in the field of animal welfare and has published several books about animal care.
She has periodically returned to television in guest appearances and in 2010 resumed singing and composing.