Art serves as superintendent of the Yokohama Police Department, a graduate of Facultas Academy despite never manifesting a Minimum ability there. He maintains a calm, protective demeanor and formal speech pattern, which sharpens when angered. His strong sense of justice and intellect propelled him to superintendent rank young, yet he harbors an inferiority complex over lacking supernatural powers.

Art shares a longstanding academy friendship with Nice and Honey. While initially viewing Nice as dependable, their bond strains due to Art's concealed jealousy of Nice's Minimum. This tension peaks when Art withholds details about a serial murder case targeting Minimum Holders, causing an unresolved argument preceding Art's apparent death.

A pivotal incident involves Art's younger brother, Skill. Discovering Skill enduring horrific experiments at Facultas Academy, Art complied with Skill's plea to end his suffering by stabbing him with a broken bottle. This act inadvertently triggered Skill's Minimum, releasing a shockwave that inflicted brain damage and memory loss on Art while granting him the Regeneration Minimum. This ability later revives Art after fatal injuries, including a pierced heart.

Following his death at Moral's hands, Art returns in the second season as primary antagonist leading Freemum. He seeks to kill Nice, believing Nice possesses Skill's heart to fulfill his brother's death wish. Art gains the power to steal and temporarily wield Minimums—including Light, Paper, Wind, Plant, Water, String, Gravity, and Enhanced Jump—by extracting liquid from holders' necks.

His motivations root in Skill's trauma and unresolved guilt, solidified when Moral reveals Art's responsibility for Skill's death attempt. This drives Art's goal to eradicate all Minimums as sources of suffering, culminating in a plan to activate Hajime's Nihilist Minimum to erase Yokohama's abilities. He ultimately reconciles with Nice six months after their final confrontation.