Nobuyo Oyama, best known as the raspy voice of Doraemon, the beloved cartoon robotic cat from the future, has died. She was 90.

Oyama died of natural causes on Sept. 29, her agency, Actors Seven, said Friday.

Created by the cartoonist Fujiko F. Fujio in 1970, Doraemon and the story of his friendship with Nobita, a good-hearted but somewhat lazy boy, became hugely popular. The manga and anime series have been read and watched by millions of fans in Japan and across the world and have been translated into dozens of languages.

In the series, Doraemon, whom Oyama voiced from 1979 to 2005, arrives from the 22nd century and helps Nobita in difficult situations, often with gadgets from the future such as an “anywhere door” and a “take-copter.”

Born in Tokyo in 1933, Oyama made her debut as an actor in a 1956 drama on Japan’s NHK public television. She had her first voice acting role in 1957 in the dubbed version of the TV drama series “Lassie.”

Oyama’s husky voice quickly became popular in anime and children’s programs. She was the voice of one of three piglets in a popular children’s puppet show in the early 1960s and of teenage boy Katsuo in the family anime series “Sazae-san” before “Doraemon.”

Oyama retired as Doraemon in March 2005 as part of a renewal of the voice actors for the main characters.

“I hope Doraemon will still be a beloved character in the distant future,” Oyama said.

In 2015, Oyama’s husband disclosed that she had developed dementia. Even so, as head of a sound arts school, Oyama was known to always succeed on the first try when she was asked to perform in her Doraemon voice.

Oyama’s agency said her funeral was held privately by her relatives.

Noriko Ohara, the original voice of Nobita, died in July.

Yamaguchi writes for the Associated Press.