TV-Series
Description
Dokusaburi Oniyama is the head of the police department's anti-phantom thief bureau and a dedicated, career officer whose primary mission is the capture of the elusive phantom thief Joker. In his mid-forties, his distinctive appearance includes a long, thin mustache, a prominent bald patch on the crown of his head, sharp teeth, and a mole situated between his eyes. He almost always wears a signature parrot green suit with a black tie and black shoes, presenting a formal and slightly comical image.

Personality wise Oniyama is defined by his zealous and near obsessive dedication to his duty. His stated reason for being is to apprehend Joker, and he pursues this goal with relentless energy, often chasing the thief across international borders. His attempts to perform an arrest, however, almost invariably fail or backfire in spectacular fashion, contributing to a comedic dynamic. He has a verbal tic of inserting the word so into his sentences, as in declaring Joker to be so under arrest. Despite his outward hostility, his obsession runs so deep that it borders on addiction. On one notable occasion when Joker was successfully captured, Oniyama found himself devoid of energy and purpose, even preparing a letter of resignation, only to tear it up in manic joy the moment he learned Joker had escaped.

Beneath this fierce exterior lies a more nuanced character who possesses a strong moral code and hidden compassion. While he desperately wants to apprehend Joker, he prefers a fair capture and shows genuine concern for the thiefs safety in dire situations, such as warning him about incoming missiles or expressing worry when Joker is poisoned. This complexity leads to a grudging respect between the two rivals; Oniyama will reluctantly cooperate with Joker during extreme crises, and Joker in turn respects Oniyama for his strong morals and duty, occasionally trusting him to handle defeated criminals.

Oniyamas motivations are not solely professional. He is a dedicated family man who cares deeply for his wife Tomoe and his daughter Haruka. His devotion to his family often plays a key role in the story, most notably when Haruka is kidnapped. In such instances, his distress is immense, and he is willing to put aside his pride to work directly with Joker to secure her safe return. Despite his authoritative position at work, he is completely unable to talk back to his wife and daughter, who often drag him out shopping on his days off.

Throughout the series, Oniyamas primary role is that of a secondary antagonist to Joker, representing the force of law that the phantom thief constantly evades. However, his character evolves from a simple obstacle into a complex figure whose relationship with Joker transcends a typical criminal-captor dynamic. He forms key working relationships with his subordinates, the junior officers Ginko Kurosaki and Momo Shirai, who assist him in his operations. His personal history includes a soft spot for the drama Bark at The Sun and the singer Saborou Kitajima, and his favourite food is fruit parfait, small details that round out his character. While he has no supernatural or advanced technological abilities, his notable skill lies in his relentless determination and his authority as the head of the anti-phantom thief bureau, commanding significant police resources in his eternal quest to bring Joker to justice. His surname itself is a pun on the Japanese word oni, meaning ogre or demon, reflecting his fierce and dogged nature.