An 88-year-old visiting researcher at a university in Kyoto was conferred a doctorate on Saturday, making her the oldest person in Japan to do so, Ritsumeikan University said.

"I'm full of emotion. I'm honored," Kiyoko Ozeki told reporters ahead of her graduation ceremony at Ritsumeikan.

Though the Nagoya resident did not enroll in the university's graduate program, her thesis helped her earn the degree.

Ozeki, who served as assistant professor at the women's junior college of Tokai Gakuen University until 1995 and is now a professor emeritus at the same institution, has been researching the cultural aspects of cloth during the ancient Jomon Period for more than 30 years.

A visiting academic at the university's Research Center for Pan-Pacific Civilizations from April 2015, she submitted her thesis to the university last September.