TV-Series
Description
North Kaiou, also known as the North Kai, is the divine ruler of Universe Seven's North Area and a prominent mentor figure in Dragon Ball Z. He is a short, blue-skinned being with pointed ears, antennae on his head, and long, catfish-like barbels extending from his cheeks. He resides on a tiny planet located at the end of the Snake Way in the afterlife, a world that possesses ten times the gravity of Earth and is shared with his two constant companions: a monkey named Bubbles and a grasshopper-like creature called Gregory.

North Kaiou possesses a deeply eccentric personality that balances high celestial authority with a playful and often childish sense of humor. He considers himself a master of puns and jokes and imposes a peculiar prerequisite on any potential student: they must first make him laugh. Despite his comedic disposition, he is profoundly wise and knowledgeable about the universe, martial arts, and spiritual energy. His jovial exterior masks a genuine and serious commitment to his responsibilities as a guardian of his quadrant, though his irritation with reckless or impulsive behavior, particularly from his most famous student, is frequently visible.

His primary motivation stems from his duty to oversee and protect the northern section of the galaxy. He is deeply concerned about threats to cosmic balance, such as the arrival of the Saiyans or the tyranny of Frieza, and he seeks to prepare worthy warriors to combat these dangers. His role in the story is pivotal as a master who provides the training and techniques that allow the heroes to overcome increasingly powerful enemies. He first appears after Goku's death in battle against Raditz, agreeing to train Goku in the afterlife. Under his tutelage, Goku learns two of the most critical techniques in the series: the Kaioken, a method of multiplying the user's power at the cost of immense physical strain, and the Spirit Bomb (Genki Dama), a sphere of energy assembled from the life force of all living things, planets, and stars. Later, during the preparations for the Cell Games, he also trains Piccolo, Tien Shinhan, Yamcha, and Chiaotzu on his planet.

Key relationships define his narrative presence. His bond with Goku is the most significant; he serves as a frustrated yet proud teacher who grows to care deeply for his student, often monitoring events from afar through telepathic communication. He maintains a cordial relationship with other deities, including the Supreme Kais, though he is of a lower rank. His death occurs during the Cell Saga when Goku teleports the self-destructing Cell to his planet, resulting in the destruction of his world and the deaths of North Kaiou, Bubbles, and Gregory. Even in death, he retains his halo and continues to support the Z Fighters from the afterlife, using his telepathic abilities to guide them and later assisting in gathering energy for the final Spirit Bomb used against Majin Buu.

Over the course of the series, North Kaiou experiences little personal character evolution in terms of personality change, but his relationship with his students deepens significantly. He transforms from a whimsical gatekeeper of knowledge to a steadfast and selfless ally who sacrifices his existence without hesitation for the greater good. His most notable abilities include the creation and mastery of the Kaioken and Spirit Bomb techniques, which he passes on to Goku. He also possesses extraordinary telepathic powers, enabling him to communicate with individuals across vast interstellar distances and to sense energy fluctuations from galaxies away. While his raw combat power is modest compared to the warriors he trains, his true strength lies in his ancient wisdom, technique creation, and strategic guidance.