Nobuyo Ōyama
大山 のぶ代
Born	Nobuyo Ōyama (大山羨代) (1933-10-16)October 16, 1933 Shibuya, Tokyo City, Tokyo Prefecture, Japan
Died	September 29, 2024(2024-09-29) (aged 90)
Occupations	Actress screenwriter voice actress singer essayist television personality
Years active	1956–2016
Agent	Actors Seven
Known for	Voice of Doraemon and Monokuma
Spouse	Keisuke Sagawa ​ ​ (m. 1964; died 2017)​

Nobuyo Yamashita (山下羨代, Yamashita Nobuyo, née Ōyama, October 16, 1933 – September 29, 2024), known professionally as Nobuyo Ōyama (大山 のぶ代, Ōyama Nobuyo), was a Japanese actress, voice actress, screenwriter, singer, essayist, and television personality affiliated with Actors Seven. Her husband was the television personality Keisuke Sagawa. She is best known for voicing the title character in the Doraemon anime series that ran from 1979 to 2005, for 26 years.

She also voiced Monokuma, the main villain from the Danganronpa video-game series, from 2010 to 2016 for the first three video games, two Danganronpa stageshows, and Danganronpa: The Animation.

In 1965, Nobuyo Ōyama began her career in anime voice acting as the character of Punch in Hustle Punch. She later voiced Katsuo Isono in Sazae-san from the show's start in October 1969 to December of that year. After a number of minor roles, she landed the role of the titular character of the long-running anime series Doraemon from April 2, 1979 until March 18, 2005 when she chose to step down due to health problems she faced in July of 2001 and she stopped voicing Doraemon in 2005. Wasabi Mizuta replaced Ōyama as the voice actress of Doraemon in the 2005 series. Five years after Nobuyo Ōyama retired from voicing Doraemon, she made a major comeback by voicing Monokuma, the major antagonist of the Danganronpa series, from 2010 to 2016.^[2]

On May 13, 2015, her husband Keisuke Sagawa revealed on a radio show that she was living with dementia, putting any planned future work on indefinite hold.^[3] This notably prevented her from reprising the role of Monokuma for future Danganronpa projects, and in April 2016, it was announced that Tarako had assumed the role.^[4] Tarako voiced Monokuma until her death in March 2024.^[5]

In April 2016, Ōyama was moved to live in an undisclosed retirement home, due to Sagawa starting to face health problems while he was taking care of her at their home.^[6] When Keisuke Sagawa died on July 11, 2017, her long-time manager Akiko Kobayashi continued to visit and look after her, per Sagawa's wishes before he died.^[7] While her dementia had progressed, it was last said in October 2017 that she was in good health despite her condition, and enjoyed interacting with the other residents and partook in activities such as choir.^[8]

Ōyama died on September 29, 2024, at the age of 90, in a hospital in Tokyo.^[9] Her death was announced by her management company on October 11.^[10][11] It was revealed in articles covering her death that over the past year, she started suffering from health problems and had difficulty speaking due to senility.^{[12] [13]} She kept visiting the hospital repeatedly over the course of the past year and kept getting discharged until her final hospitalization on September 19.^{[14] [15]}

Following her death, a private funeral was held by her relatives before the news was publicized.^[11][16] At her funeral, it was said that there was a photograph of her late husband Sagawa, chestnut yokan from Toraya, and a stuffed toy of Doraemon by her side inside the coffin she was in.^[17]

At the end of episode 832 of the Doraemon (2005) series, which was broadcast on TV Asahi on October 12, 2024, a message of condolence and gratitude for Nobuyo Ōyama with scenes from the Doraemon (1979) series, playing in a montage were broadcast in her memory.^[18]

The voice actress for Doraemon since 2005 in the current series, Wasabi Mizuta, expressed grief and condolences over Ōyama's death on her official blog on October 12.^[19][20]

On October 13, the Sazae-san anime had a memorial caption for Ōyama at the start of the first episode broadcast that day.^[21]

• Official agency profile^{[permanent dead link‍]} (in Japanese)
• Nobuyo Ōyama at Anime News Network's encyclopedia