TV-Series
Description
Kaîoh, also known as the North Kaio, is a deity who rules over the North Quadrant of the universe in Dragon Ball Z Kai. He is a short, blue-skinned humanoid with pointed ears and a pair of antennae on his forehead, which are used for telepathic communication. He is never seen without his signature pair of teashade sunglasses. Kaîoh lives on a tiny, personal planet located at the very end of the long, winding Snake Way in the Other World, an afterlife realm. Despite its small size, the gravity on his planet is ten times greater than that of Earth. His only companions on this otherwise solitary planet are a pet monkey named Bubbles and, in the anime, a grasshopper named Gregory. He also owns a vintage car, which he enjoys driving around his small world.

Kaîoh is known for his eccentric and humorous personality. He possesses a great love for bad jokes and puns, and as a test for potential students, he famously requires them to make him laugh before he agrees to train them. While his sense of humor can make him appear silly and imperturbable, he is also a being of great wisdom and intelligence, possessing vast knowledge about the universe and its many powerful warriors. He sometimes exhibits immature traits, especially when interacting with his fellow Kais from other quadrants, as they often bicker and provoke each other in a sibling-like rivalry. Despite being a god, Kaîoh is not immune to frustration and can become genuinely angry, particularly when his peace is disrupted or his planet is endangered.

Kaîoh's primary role in the story is that of a martial arts master and mentor. He is most famously the teacher of the protagonist, Goku. After Goku dies fighting Raditz, he is directed to travel to Kaîoh's planet to train in preparation for the arrival of the Saiyans Vegeta and Nappa. Kaîoh agrees to train Goku, who successfully makes him laugh, and puts him through a demanding and unconventional regimen that includes catching Bubbles in the planet's intense gravity. Following his training with Goku, Kaîoh also takes on Yamcha, Tenshinhan, Chiaotzu, and Piccolo as students when they arrive in the Other World after being killed by the Saiyans.

Throughout the series, Kaîoh serves as a distant but crucial advisor. He uses his universal telepathy to communicate with Goku and the other Z-Fighters on Earth from his small planet, offering strategic advice during their battles against foes like Vegeta and Frieza. He is also a source of exposition, revealing the history of the Saiyans and the threat posed by powerful villains.

Kaîoh's most significant contribution to the series is his creation of two legendary techniques, which he teaches to Goku: the Kaioken and the Spirit Bomb, also known as the Genki Dama. The Kaioken is a technique that multiplies the user's ki and physical abilities for a short burst, while the Spirit Bomb is an ultimate attack that gathers energy from surrounding life forms and nature to form a powerful sphere of destruction. Through these techniques, Goku is able to overcome opponents who vastly outmatch him in raw power. Kaîoh himself admits that he is not a particularly strong fighter, and that Vegeta and Nappa were more powerful than him during the Saiyan Saga. His true strength lies in his knowledge, his techniques, and his unique abilities, most notably his unparalleled telepathy which allows him to converse with any person across the universe.

A key event in Kaîoh's arc is his accidental death. During the battle with the bio-android Cell, Goku uses his Instant Transmission to teleport the self-destructing Cell away from Earth, choosing Kaîoh's small planet as the destination. The explosion kills Cell but also destroys the planet, killing Goku, Kaîoh, and his pets Bubbles and Gregory. This event leaves Kaîoh quite angry at Goku for his lack of foresight. Because he was already residing in the Other World, his death does not significantly change his circumstances, but it becomes a point of mockery from the other Kais. Despite this, he continues his role as a mentor and advisor from the afterlife.