Ueki's Law is a principle from the manga and anime series The Law of Ueki, created by Tsubasa Fukuchi. It states that a person can gain a special ability by using a specific talent to turn something into a different form. For example, a character might transform trash into a tree, showcasing their unique power. The law emphasizes creativity and resourcefulness, as characters must think outside the box to utilize their abilities effectively. This concept drives the plot and character development, encouraging viewers to consider how they can use their own skills in innovative ways.