She was a smoker.
Ahh, it's a shame but it was her own fault, the more callous might say. Maybe so. She made a bad choice (if starting when you are young and foolish and remaining addicted is a choice), but she paid with her life. What's the Japanese government's excuse? Until 1985 they owned Japan Tobacco and today they still own 50 percent, and resist pressure to tax fags more. You can check the figures and make your own mind up about Japan Tobacco and the government.
Our Man has made his mind up. Rest in Peace, Miyano-san. Rot in Hell, Japan Tobacco, and all your stinking friends.