As a teenager, Haruchiyo used to be a calm demeanor and rarely talks. However, it is later revealed that he is also quite manipulative and is exceptionally good at deceiving other people. As an adult, he seems to be more extroverted, blunt, and loud. He is ruthless and displays psychopathic tendencies.His most notorious trait is his fanatical idolatry towards Manjiro. He takes sadistic delight and notorious euphoria when executing traitors. He is a katana-crazed and a drug addict.