Myocarditis — inflammation of the heart muscle — linked to an influenza infection killed Japanese child performer Hirata Runa, who sang under the stage name Luna-chan, her agency said. She was eight years old when she died in the early hours of Friday morning, Sept. 25, 2026.
Hirata was one of the Nagoya trainees of the DIANNA Project, the agency said. Her family confirmed that she died at around 4 a.m. on Sept. 25 in a tribute posted through her official account. She was in her third year of primary school.
Her Final Stage Appearance
Her last stage appearance came five days earlier, at the DIANNA Project’s Regular Live Vol.70 concert in Nagoya, Japan, on Sept. 20. Supporters reacted with shock to the news, having watched her take that stage in what looked like good health only days earlier.
After that show, she posted a cheerful note of thanks to the people who came to watch her. “Thank you again today. It was so much fun,” she wrote. The audience at the show’s third part, she added, would hopefully have just as good a time.
Agency Asks for Privacy
The agency said it regretted to announce the death of Hirata, one of its Nagoya trainees, of myocarditis associated with an influenza infection. The DIANNA Project is a Nagoya-based talent program and girl-group scheme that develops and markets young J-pop “idols” based on their personality and public image.
The agency said that, following the wishes of her bereaved family, the wake and funeral took place with only close relatives present. It offered its deepest gratitude to the fans who supported her and to everyone involved in her short career.
The agency asked the public to respect the family’s feelings and to refrain from individual inquiries or media requests about her death, or from posting questions about it on social media, because the funeral had already been held in private.
Family Thanks Fans and Staff
“One third of Runa’s life was spent as an idol,” her family said in the tribute shared through her official account, adding that she had loved everyone very much.
The family said it was sorry to deliver such sudden news. Its thanks went to the fellow idols who had stayed close to her, to the fans who had followed her, to the agency staff who had turned her into an idol and to every other person connected to her. The family asked supporters to hold on to a place for her inside themselves, and relayed her own gratitude for everything up to now.
Beyond the agency’s announcement, no further medical details or treatment history have been released.
Other Losses in Japanese Pop
Her agency, Big Apple, confirmed on Friday, Dec. 6, 2024, the death of Singer-actor Miho Nakayama, a figure in the early J-pop scene, who was found dead at her home. She was 54.
Tokyo was Nakayama’s birthplace on March 1, 1970, and she began her entertainment career in 1985, balancing music and acting from the start. She starred in director Shunji Iwai’s 1995 romance “Love Letter,” released in the United States as “When I Close My Eyes.” Nakayama is survived by a son she shared with her former husband, musician Hitonari Tsuji.
