Ryuichi Yoneyama (born 8 September 1967) is a Japanese politician who served as Governor of Niigata Prefecture. Before entering politics, he worked as a radiology researcher at the University of Tokyo Hospital and was trained as a lawyer. Elected governor in 2016 as the opposition's unity candidate, he took a cautious stance on restarting the Kashiwazaki-Kariwa nuclear power plant. He resigned in 2018 after reports that he had paid women he met through dating sites. He later won a seat in the House of Representatives in 2021 as an independent.
Early career
Born in Niigata Prefecture, Yoneyama studied medicine at the University of Tokyo and earned his doctorate in 2003. He passed the bar examination in 1997 and later worked as a lawyer specialising in medical malpractice cases. His medical research experience led to a lectureship in healthcare policy at the university's Research Center for Advanced Science and Technology. Several unsuccessful attempts to enter the national legislature followed, first as a Liberal Democratic Party candidate and later for other parties.
Governorship and resignation
Yoneyama was elected Governor of Niigata in 2016, his first public office. He opposed TEPCO's push for an immediate restart of the Kashiwazaki-Kariwa plant and withheld the authorisation needed for operations to resume, placing him at odds with the national government. In April 2018 he admitted to paying women he met on dating sites and resigned, leaving office later that month.