Mister Kaneari, a wealthy affiliate of the Gold Group, channels significant resources into designing elaborate traps to capture or defeat phantom thieves targeting his valuable treasures. His persistent focus centers on outsmarting these thieves. Physically, he possesses light coral pink hair, purple eyes, a long pointed nose, and a mole above the right side of his mouth, typically depicted with sharp teeth. His attire features a fancy suit with golden trim around the head area, golden buttons, and red-purple cuffs adorned with lavender lacy trim, paired with matching red-purple dress pants, white shoes featuring dark brown soles, and square golden-rimmed glasses.

A defining personality trait is his pronounced overconfidence in his anti-thief plans and traps, which frequently leads to miscalculations causing unintended explosions damaging his own property. He holds a notable attachment to a pink teddy bear named Kintaro-chan. Twisting the bear's nose activates a plot-specific device, yet inevitably triggers an explosion; a recurring comedic element involves him inadvertently pressing the nose button with destructive results. He habitually ends his sentences with "indeed" and employs lethal traps within his properties.

His relationship with assistant Kaneko evolves significantly; by the events of episode 30, they are married. He demonstrates affection, using the nickname "sassy-chan" and expressing possessiveness, such as discomfort when external forces like Cupid's love arrow influence her affections. His primary role involves deploying his wealth to create challenging, dangerous scenarios for phantom thieves, operating as a persistent adversary driven to protect his treasures through increasingly sophisticated, often destructive countermeasures. His character remains consistent in these objectives and the comedic failures stemming from his overconfidence and reliance on Kintaro-chan.