A cute boy in a blue jiu-jitsu outfit, ready in a fighting pose, with a simple chibi character design, 3D isometric render, on a black background, with big brown eyes and dark hair, white skin color, in the style of Pixar animation, wearing a karate belt around his waist. The overall look should be playful yet serious, suitable for an animated film or game art, focusing on vibrant colors and detailed textures that give it a three-dimensional appearance.