Ogma, a middle-aged red deer, possessed prominent curling antlers and consistently wore standard square-framed glasses. His attire featured an emerald green suit layered over a cedar brown collared shirt, a dark gray tie, and brown shoes or boots. As owner and leader of the influential Horns Conglomerate, he held significant power. Privately sterile, Ogma purchased young Louis from the Black Market for ¥7,000,000 to groom him as a successor. His parenting approach was severe and calculated. Immediately after acquiring Louis, Ogma locked the child in a room with hostile carnivores, providing only a knife for defense. When Louis attempted suicide to avoid being consumed, Ogma intervened, impressed by this resolve. He declared his intent to raise Louis as his biological son, believing Louis possessed potential for societal change.

Ogma maintained an enigmatic personality, often conveying approval or disappointment through material gestures—such as gifting Louis a 500,000-yen bicycle after an imperfect test score. Stern and demanding of strength and resilience, he occasionally displayed protectiveness, like rushing to Louis's room armed with a taser prod upon hearing a scream, though the incident proved harmless. Their relationship remained complex: Ogma provided elite education and resources but imposed crushing pressure. He later arranged Louis's marriage to fellow red deer Azuki to secure the family lineage and corporate legacy. After Louis lost a foot in a conflict involving the Shishigumi, Ogma funded his prosthetic replacement.

Ogma died from injuries sustained in a car crash, as confirmed in Chapter 165 of the manga. His death triggered Louis's immediate succession as president of the Horns Conglomerate. The name "Ogma" references the Gaelic god of speech and learning—an ironic contrast to his taciturn demeanor. Additionally, the kanji for "Oguma" coincidentally translates to "small bear," a detail underscored when Louis later regarded both Ogma and the lion Ibuki as father figures.