Korin

Korin has inhabited his tower for over 800 years, serving as a gatekeeper between the mortal world below and the divine realm above. Any warrior who wishes to train under Earth's Guardian must first climb the tower and prove their worth by catching Korin, a task that tests both physical speed and mental patience. Master Roshi, one of the greatest martial artists in history, took three years to accomplish this feat. Goku managed it in three days, marking him as an exceptional talent from the very beginning.

Beyond his role as a test, Korin provides the Sacred Water, which was believed to grant immense power to anyone who drank it. In truth, the water itself has no special properties; the real training comes from the effort required to obtain it. Korin also maintains the Ultra Divine Water, a genuinely potent and extremely dangerous substance that can unlock dormant potential in those strong enough to survive drinking it. Goku uses this water to power up before challenging King Piccolo.

Korin's most enduring contribution to the series is his cultivation of Senzu Beans, magical beans that instantly restore a person's health, stamina, and ki to full capacity. A single bean can heal mortal wounds, restore days' worth of energy, and even satiate hunger for ten days. The Z Fighters rely on these beans so heavily that their supply (or lack thereof) often becomes a critical plot point during major battles.

Throughout Dragon Ball Z and Super, Korin continues to grow and provide Senzu Beans to the fighters, with Yajirobe typically serving as the delivery courier. The beans' scarcity adds tension to the story; Korin can only grow a limited number at a time, and there are never quite enough when the situation is most dire. This limitation prevents the beans from becoming a narrative crutch and keeps the stakes high during prolonged battles.

Despite his small stature and unassuming appearance, Korin commands deep respect from everyone who knows him. He has witnessed centuries of conflict and trained multiple generations of martial artists, giving him a perspective on the world that few other characters possess. His calm wisdom, delivered with a dry wit, makes him a beloved fixture of the Dragon Ball universe.