Grand Kai

Grand Kai (大界王, Dai Kaiō; lit. "Grand Kaio" or "Grand Lord of the Worlds") oversees the four Kais, North Kai, West Kai, South Kai and East Kai, who rule over the four quadrants of the universe. Grand Kai is portrayed as an aged hipster, usually wearing jeans and a denim jacket, and constantly listening to rock music on his boom box. He wears black Wayfarer sunglasses, and owns a Blue 1958 Chevrolet Impala Convertible.
Goku is brought to Grand Kai in the beginning of the Great Saiyaman Saga by North Kai. His home is the Grand Kai's planet. He is considerably stronger than the other Kais and is known to be the greatest fighter in the four galaxies. Even though he is the teacher of the greatest warriors in the universe, Grand Kai (much like North Kai and Master Roshi) is more of a sweet and a kind grandfatherly figure than a traditional disciplinarian.

Paying no heed to respectful-but-cold formality, he lovingly treats his social-inferiors as equals and dotes on them as if they were his own grandchildren. In the Japanese version, he affectionately addresses younger warriors with suffix of "-chan" (e.g., Goku-chan, Paikuhan-chan), a term of endearment usually reserved for young children.

It is revealed in the World Tournament Saga that despite his position, he is not authorized to set foot on the Sacred World of the Kais.

Information from:
http://dragonball.wikia.com/