The Strange Case Of Dr. Jekyll And Mr. Hyde by Mitsu Yamamoto

A respected Victorian scientist experiments with a chemical potion intended to separate his moral character from his darker impulses, only to unleash a smaller, cruel alter ego who commits increasingly violent and immoral acts; as the transformations grow harder to control, the scientist's double life unravels, bringing murder, blackmail, and a desperate confession that exposes the terrifying fragility of identity and the hidden capacity for evil within a single person.