When Goku enters the "Sacred Land of Korin" searching for his Grandpa Gohan's Four-Star Ball, he soon discovers that the ball is held by the native inhabitants, Bora and Upa. Gratefully, Bora gives the ball to Goku and tells him of the legend of the colossal tower, so high that not even airplanes can reach the top; if a person manages to climb to the top and drink the "Sacred Water" held by Korin, the Master of Combat, their strength and speed will be tremendously increased.
Learning of their defeat, the Red Ribbon sends the hired assassin Mercenary Tao, who easily overpowers Goku and nearly kills him, if not for the Dragon Ball hidden in his clothing. After coming to, Goku realizes his need to become stronger and begins the ascent, climbing throughout the day and into the night, sleeping with his tail clinging tightly to the handholds. After a day of straight climbing, an exhausted Goku reaches the top and encounters the white cat-immortal, Korin, who is insulted at the boy's disbelief that he is the legendary Master. After reading Goku's mind and finding his intentions pure, Korin tells the boy that he can have the Sacred Water. Goku leaps to grab it, but the cat immediately snatches it away, hooking it to his stick and declaring that the boy can indeed have it — if he can take it.
Even Goku's superhuman agility is no match for the cat, as he leads Goku on a chase around and around the tower, matching Goku's After Image Technique with his own, eventually becoming bored with the "workout" and calling an end for the day. An exhausted, yet curious Goku asks if anyone has managed to reach the water; the cat responds that the only one who did was Goku's old teacher, Master Roshi, which shocks the boy. He is further shocked when, asking how long it took, Korin responds with three years. The next day, Goku awakes to find Korin dumping "garbage" over the side of the tower--including his Grandpa Gohan's Four-Star Ball! Furious, he immediately runs down the tower to retrieve it and climbs it again, while the old cat looks on with satisfaction; what took a day previously has now only taken 3 hours, a sign of the boy's growing strength. After three days of chasing and climbing, a determined Goku finally manages to outmaneuver Korin and take the bottle of Sacred Water from him; after drinking it, however, he doesn't notice any strength increase at all. Korin informs him that it is just tap water; it was Goku's intense exertion that made him much stronger and faster than before. A grateful Goku thanks Korin for the training, and climbs down the tower to face Mercenary Tao again. After Goku tells Mercenary Tao about the Sacred Water, the assassin climbs the tower to get the power for himself. Korin, however, sensed a wicked man like Mercenary Tao and tricked him, by giving tap water.However, Korin does in fact have special water that unleashes the drinker’s inner power — the Ultra Divine Water; however, the water itself is so dangerous that he refuses to let Goku journey to retrieve it until learning that the legendary King Piccolo had been released — tasting a single drop of the Ultra Divine Water nearly kills Yajirobe, sending him into spasms of agony. After a grueling trek and overcoming numerous obstacles (in anime only), Goku reaches the Ultra Divine Water and drinks deeply, sending him into agony as well, but also giving him the power needed to defeat King Piccolo.
In addition to this, Korin is the only one who grows the Senzu Beans which heal wounds and are equivalent to eating ten days worth of food. Korin Tower is the only place in the world (and perhaps the universe) they are grown, and so these magic beans are quite valuable. The Senzu Bean are used frequently in Dragon Ball Z to restore energy in battle, and many a time they save the lives of the Z Fighters. The beans are limited in number and are difficult to grow, and so Korin only gives them to the Z Fighters in time of need or before a battle. Usually no more than five are carried at a time.
In Dragon Ball Z he shows up from time to time, giving a Senzu Bean to Goku when he is revived, and training the Z Warriors. Yajirobe eventually ends up living with him in the tower. Korin makes a cameo appearance in Dragon Ball GT, in episode 40, Piccolo's Decision.
The name is derived from karin, the Japanese name for the Chinese quince. His tower, the "Korin Tower" (カリン塔 Karin-tō), is a play on a type of fried dough cake called "karinto" (花林糖 karintō), which fits the common theme of the characters being named after foods.
After Image Technique
- In the King Piccolo Saga, Goku's Flying Nimbus was destroyed, but when he climbed Korin Tower, Korin told him they can never be destroyed. However, for some reason, in the 3rd Dragon Ball movie, "Mystical Adventure", Korin is surprised to see a cloud like Flying Nimbus.
- Akira Toriyama used his own cat as a model for Korin and drew him while the cat was sleeping. This is why Korin's eyes are closed.
- In the video game Ōkami by Capcom, the cat brush god Kabegami can be reached by climbing a tower that reaches to the skies, similar to the Korin Tower.
- In the Manga, Karin had blue fur. In the anime, it was changed to white.