Throughout a majority of the story, the character known as Kami on Earth is a wise Namekian who no longer even remembers his real name. It was revealed, however, that his father's name was Katas. As a nameless Namek, he hatched on Planet Namek in 250 AD and as a child was launched by Katas into outer space in a Namekian spaceship which requires at least a basic knowledge of Namekkugo, the ancient Namekian language, to pilot.
At some point in his adult life he arrived at Kami's Lookout, the home of the guardian of Earth at the time and became his apprentice in hopes the aging guardian would choose him to be his successor when he died. He became Kami after separating the evil from of himself in order to attain the position, forming an evil twin brother calling himself King Piccolo who shared a lifeline with him (were one to die the other would die aswell). He watched over the Earth from from his lookout during King Piccolo and his mutated sons initial rampage but eventually in a serious of long, complicated circumstances they were defeated by the forces of Mutaito.
Some 300 years later, at the conclusion of the 22nd World Martial Arts Tournament Emperor Pilaf frees King Piccolo and soon after a human named Krillin is murdered by Piccolo's newest son, Tambourine. It's later revealed King Piccolo seeks Dragon Balls to restore his youth before taking over the world again. King Piccolo eventually summons Shenron and has his wish granted, but soon after Piccolo kills Shenron to prevent anyone else from using the dragon against him. The next day King Piccolo confronted and killed by a young Goku, who had in turn been almost killed himself by Piccolo the day prior.
With all his sons dead and himself mortally wounded, King Piccolo spits out one last egg containing his son and reincarnation Piccolo Jr. intended to exact revenge on Goku and also sparing Kami's life in the process, he then explodes. Shortly after Goku arrives at Kami's mysterious lookout and meets his loyal servant Mr. Popo. Kami agrees to meet with Goku without the long rigerous training required to beat Mr. Popo, and upon seeing Kami Goku mistakes him for King Piccolo and charges at him, but Kami merely flicks him away. Kami revives Shenron so that all the innocents killed by Piccolo and his sons can be removed from limbo and brought back to life, but then informs Goku he must train under him for three years in order to defeat Piccolo Jr. who would be seeking to challenge him at the 23rd World Martial Arts Tournament.
Three years later Goku arrives at the tournament, but Kami enters aswell inside the body of Hero after realizing Piccolo Jr. is even stronger than his father now. Towards the end of the tournament Kami attempts to trap Piccolo Jr. with the Evil Containment Wave but Piccolo Jr. reverses it and Kami finds himself trapped within a small bottle. Later Goku frees Kami and eventually defeats Piccolo Jr. but shows him mercy because Kami would die aswell were he to kill him. Still full of guilt Kami offeres Goku his position, but Goku declines to keep his promise to marry Chi Chi and flies off on the nimbus cloud with her.
Five years later Kami continues to watch over the Earth, and it appears Goku and Piccolo clashing once again is inevitable, but one day a mysterious alien named Raditz lands on earth in search of his brother Goku. Raditz' power and aspirations are even worse than Piccolo's in that Raditz is far stronger and could also destroy the Earth, rather than make it his kingdom like Piccolo aspired to. Eventually with Piccolo's help and an intervention from his son Gohan, Goku defeats Raditz, but dies himself as a result. After learning two more Saiyans are on their way to Earth Kami is able to get Goku training with King Kai himself, a powerful being that is located at the end of Snake Way. During the initial struggle with Vegeta and Nappa Piccolo is killed when he sacrifices himself to save Gohan, and Kami dies soon after, Goku eventually arrives and narrowly saves the Earth from Vegeta, but in the end lets him live. He remains dead until the Frieza Saga.
Kami's role diminished greatly after the heroes return to Earth from Namek from what it had been prior to their journey, and by the Androids Saga he was no longer needed for training or wisdom. Because of this, and out of concern for a then unknown threat, he agrees to fuse with the reincarnated and redeemed Piccolo in the Imperfect Cell Saga to return to being the original nameless Namekian. The new Piccolo would go on to fight Cell but never manages to kill him through various complicated events. Because he is a Namekian, he also has the ability to create Dragon Balls, but this is not a skill that most Guardians would have.
Despite being essentially a god, the person who acts as Kami is not necessarily supremely powerful. Kami was the strongest fighter in the series during and after King Piccolo's final rampage that was ended by Goku, but by the start of Garlic Jr. Saga, virtually all of the main Z Fighters and their enemies are more powerful than Kami and his role becomes more of a support one, and Piccolo even remarks once, "the only reason you even exist now is for the Dragon Balls".
- Levitate: Kami can fly by simply controlling his energy and push out ki from underneath, as he was seen doing in Hero's body in the World Martial Arts Tournament.
- Magic Materialism: Kami used this to restore Goku's clothes that were wrecked by Piccolo in the 23rd World Martial Arts Tournament.
- Kai Kai: Kami can instantly appear at King Yemma's front desk in the afterlife without requiring the use of an energy signature to home in on.
- Eye Lasers ("Beam Eye"): a thin laser-like beam is shot from both eyes.
- Evil Containment Wave ("Magic Seal Attack"): Kami attempted this technique to seal Piccolo Jr. in the 23rd World Martial Arts Tournament but ended up sealed himself by Piccolo Jr.'s Evil Containment Wave.
- Shock Wave: an invisible ki blast of a sudden wind attack that can be launched theoretically from any part of the body.
- Telepathy: the ability to channel one's thoughts to another being.
- Regeneration ("Regrowth"): a Namekian trait that allows Kami to regenerate as long as the nucleus in his head, survives (Note: Kami is never shown using Regeneration, however he is probably capable of it).