Hirata Runa was only eight years old when she stepped on stage in Nagoya on September 20. She smiled, sang, and thanked her fans online afterward, saying she had enjoyed the day. Just five days later, she was gone. Her agency, DIANNA Project, said she died from myocarditis caused by influenza.
Her death came at 4 a.m. on September 25. The announcement was made three days later, on September 28, through her official account. The agency expressed gratitude to fans and asked for privacy for her family. The wake and funeral were held quietly, with only close relatives present.
Runa had been a trainee with DIANNA Project, a Nagoya-based idol group. She was born April 16, 2018, and loved video games and travel. She was still a child, but she had already begun to build a following. Her family said they were thankful to the idols who had been kind to her, the fans who supported her, and the agency that helped her chase her dream.
Her final post online showed her smiling after the concert. She thanked everyone who came and said she had fun. That message now reads like a farewell. It was her last public moment before the illness took her life.
The agency explained that myocarditis is inflammation of the heart muscle. It can weaken the heart’s ability to function and is sometimes linked to viral infections like influenza. For Runa, the illness proved fatal in just days.
Her family asked that she remain in the hearts of those who knew her. DIANNA Project also asked people not to send questions or requests, saying the family’s feelings should be respected. The group said they hoped her memory would live on quietly.
Nagoya, a major city in central Japan, was where Runa trained and performed. It is one of the country’s largest metropolitan areas, sitting between Tokyo and Osaka. For Runa, it was the place where her short career began and ended. Her story is now a reminder of how fragile life can be, even for the youngest among us.







