Ms. Nakayama was originally scheduled to perform a Christmas show in Osaka on Friday, but canceled her performance, citing ill health.
A statement on her website, released by her agency, confirmed her death on Friday.
“We are stunned by the suddenness of the incident,” the statement said, adding that the cause of her death has not been confirmed.
Ms. Nakayama, who was one of Japan’s most popular teen idols in the 1980s, also had a distinguished acting career – most notably as the lead in the 1995 film Love Letter, about a distraught widow’s letters to a stranger.
The film was a hit at the box office and received critical acclaim both at home and abroad. Ms. Nakayama’s performance won her several Best Actress awards.
Ms. Nakayama leaves behind a son who is in the care of her ex-husband, the musician Hitonara Tsuji.
