8-year-old Japanese idol trainee Hirata Runa “passed away peacefully” due to "myocarditis resulting from influenza,” just 5 days after performing in concert. Myocarditis is “inflammation of the heart muscle.”

Source: https://people.com/8-year-old-pop-star-dies-from-flu-related-condition-12156188

Archive: https://archive.li/qQdHW