In a realm ruled by mighty celestial beings, a grand competition unfolds to determine the realm's next ruler! Each Celestial bestows a unique power upon a chosen middle school student to act as their champion. These empowered children engage in fierce battles where the defeated are eliminated, and the victors acquire new abilities! Amidst this spectacle, the seemingly ordinary Kosuke Ueki is unexpectedly selected as a participant. Endowed with the extraordinary ability to transform garbage into lush flora, Ueki faces two significant hurdles: unawareness of his role in the contest and the puzzling challenge of triumphing in combat with a power seemingly limited to tree creation from waste.