Bou Bou, called Leo in Japanese media, serves as the central figure throughout the Jungle Emperor narrative. He is the son of Panja, the white lion ruler of an African jungle. After humans kill Panja, Leo is born on a ship carrying his captured mother. She directs him to return to Africa before dying in a storm. Marine life aids Leo as he swims ashore, guided by celestial shapes evoking his mother. Initially stranded near humans, a boy named Kenichi raises Leo. During this time, Leo masters human speech, adopts walking upright, and experiences human civilization, including periods in European cities. This upbringing forms his conviction to integrate human cultural aspects into animal society. Returning to the wild, Leo faces down rival lions like Bubu (Claw) who challenge his leadership. He implements agricultural practices, educational facilities, and diplomatic measures among jungle inhabitants. His rule prioritizes safeguarding vulnerable species and mediating human-animal conflicts, though repeated betrayals and captures foster increasing wariness toward humans. As an adult in later stories, Leo marries his childhood companion Lyra and fathers two cubs, Rune and Rukio. His character shifts toward a more austere and protective demeanor, balancing family duties with jungle stewardship. This phase shows him engaging more readily in physical confrontations, sometimes wounding or killing threats to his family or territory. Key trials include rescuing his son from human captors, battling poachers, and confronting environmental disasters like dam construction that ravage animal habitats. Narrative conclusions vary: the 1966 anime preserves Leo's family, offering hope instead of the original manga's tragedy. The 1997 film aligns with Osamu Tezuka's vision, depicting Leo sacrificing himself during an expedition to Mt. Moon; his deliberate impalement on a knife provides sustenance and shelter for a companion, enabling human allies to obtain medicine saving the jungle from plague. Other portrayals include a 1989 series examining Leo's violent psychological phases and self-imposed exile, and a 2009 special showing him initially timid before demonstrating courage during an orchestrated jungle crisis. Physically, Leo is consistently a white lion with blue eyes and black-tipped ears and tail, though later versions sometimes feature scarlet or russet eyes. Early manga depicts him wearing trousers and suspenders in youth. His core ideology focuses on fostering mutual understanding between species, though his methods evolve from idealism to pragmatic leadership across his lifespan.