Romantic mission between an underdog actress planning a fake marriage VS ambitious soon-to-be brother-in-law who opposes.

When the crown prince is killed, his twin sister assumes the throne while trying to keep her identity and affection for her first love a royal secret.

Based on the longest-running web-based comic series “Ma Eum Ui Sori” in Korea, “Sound of your heart” is a story about Cho Seok, an aspiring comic writer, and his strange…