Law of Ueki

Summary: 

    The story starts out with the Battle of the Supernatural Powers, a tournament to decide who will be the next god of Heaven (rendered as Kami (天界人) in the Japanese version).

Each candidate (100 in total) is required to choose a junior high school student (middle school) to act as their fighter. The student is given a unique power and told to eliminate as many enemies as possible. The winning god Candidate will become The New god of Heaven and the winning student will receive the Blank Zai (or talent), a talent that can be anything they choose.

While this leads many students to thoughts of greed and selfishness, Kosuke Ueki decides to take it upon himself to win this tournament to keep that power away from those that would abuse such a gift.