After the success of Jungle Emperor in Japan, Dr. Tezuka ventured into creating a sequel in 1966 titled 'The New Jungle Emperor' or 'Onward, Leo!' However, due to producing the series independently and staying true to his original manga's darker themes with character deaths and somber episodes, NBC hesitated to air it without a deal. It wasn't until 1984 that the series, rebranded as 'Leo The Lion,' reached international audiences. Set a few years post the original Kimba series, the show revolved around an adult Kimba and his mate Kitty raising two cubs, particularly focusing on Rune, the male cub, as he navigated growth and strength akin to his father. To comply with legal constraints, the English version retained the original Japanese names for all characters.