"Heartwork: Symphony of Destruction" follows Asakura Yuu, a mild-mannered university student whose life changes abruptly when he discovers a duffle bag containing a gun and assassination orders. Embracing a dark new persona, Yuu embarks on a dangerous path filled with nonstop sex, violence, and intrigue, balancing his lethal new role with the challenges of school, seductive encounters, and pursuing enemies from both the syndicate and police, all while confronting the mysterious original owner of the gun.