Dai Kaio

大界王

While Grand Kai does not appear in the Dragon Ball manga, he is mentioned within it. In fact, his characterization in the anime was suggested to the production staff by the manga's author, Akira Toriyama, himself.
Grand Kai is depicted as an elderly hipster, typically dressed in jeans and a denim jacket, and constantly listening to rock music on his boom box.
Although he serves as the teacher to the universe's greatest warriors, Grand Kai is more of a sweet and kind grandfatherly figure than a traditional disciplinarian (much like North Kai and Master Roshi). Disregarding respectful-but-cold formality, he lovingly treats those socially beneath him as equals and dotes on them as if they were his own grandchildren.