TV-Series
Description
Lum's father, sometimes known as Mr. Invader and given the personal name Satoshi, is the leader of the oni, an alien race of large, horned, ogre-like beings. He is the one who commands the oni invasion fleet when his people first arrive on Earth, and it is he who proposes the challenge that decides the planet's fate: a game of tag between a randomly selected human and his daughter Lum. When the human chosen is Ataru Moroboshi and Ataru wins by grabbing Lum's horns, her father honors the outcome, accepts Ataru as his son-in-law, and abandons the invasion rather than go back on his word.

Physically he is an enormous and imposing figure, with the bulky frame, horns, and tiger-striped clothing typical of his species. His size, deep voice, and habit of shouting make him seem menacing, and he does not always realize how frightening others find him. Beneath this intimidating exterior he has a goofy and excitable side, and much of his bluster is used for comic effect. He is portrayed as somewhat overweight, prone to raising his voice, and given to dramatic displays of authority. His personality mixes warlord pride with family warmth: he is decisive, pragmatic, and very aware of his position, yet he is also affectionate toward his daughter and willing to accept situations he cannot control.

His central motivation is the welfare of his family and his people. He acts as a father first, wanting security and happiness for Lum, while also carrying the responsibilities of the oni chieftain. His decisions tend to be practical rather than sentimental; once the Earth challenge is lost, he adjusts quickly and treats the resulting engagement as binding because honor and results matter to him. He shows the same pragmatism in later dealings with Earth, acting as a negotiator rather than a warmonger. He is also protective, and at times he tries to guide Lum's life, such as when he advises her to return home after Ataru treats her coldly or when he arranges large gatherings to present alternative suitors. Lum refuses to leave Ataru, and her father ultimately respects her choice. In domestic matters he is far less commanding: he is openly afraid of his wife, an elegant and strong-willed woman who is not above throwing him out of the house, as when she reacts to his anger over being put on a diet.

His role in the story is most important at the beginning, when he sets the entire situation in motion by challenging humanity to the tag game. Afterward he appears as a recurring supporting figure, often turning up to negotiate, to test or observe Ataru, or to involve himself in Lum's life. His presence provides an authority figure from the alien side and a connection between Lum's homeworld and her new life among humans. In the original Japanese version he speaks with a Kansai accent, which adds to his colorful and approachable characterization despite his fearsome appearance.

His key relationships are defined by family bonds. With Lum he is affectionate and indulgent, and she calls him by a familiar word for father; he supports her even when he disapproves of her choices. With Ataru he is generally cordial once the challenge is settled, addressing him as son-in-law, and he is willing to accept the human into the family, though his tolerance is tested by Ataru's behavior. With his wife he is submissive and easily cowed, a reversal of the fearsome image he projects elsewhere. He also interacts with Ten, Lum's young cousin, treating the boy as part of the same clan while keeping an eye on his troublesome behavior.

Over the course of the series his role develops from that of an invader determining Earth's fate to that of a family man adjusting to an unusual son-in-law. The proud warlord who leads the assault becomes a figure who accepts the outcome with good grace, supports his daughter's happiness on her own terms, and trades his conquest ambitions for a more domestic and comedic presence.

His notable abilities are tied to his position rather than to any unique power. As an oni he belongs to a race with superhuman traits such as flight and the generation of electrical shocks, and he shares the species' characteristic horns and sturdy constitution. More distinctive is his military and political authority: he commands the invasion fleet, has access to advanced alien technology, and can rally his people and host large-scale events. His most effective personal tools are his sheer physical presence, his loud and commanding voice, and the weight of his word as the oni leader, which he treats as binding once given.