A child character who is a scientist and/or inventor.
A Kid Scientist is young (early teens or below) and has an interest in science that goes beyond simply learning about their favorite field. Kid Scientists are distinguished from other bright, nerdy children because they don't just know a lot about their area of interest, they are, in some way, active participants. They do research, perform experiments, or build Homemade Inventions in their bedrooms. The Kid Scientist is usually a young Science Hero, but less-sympathetic portrayals are possible. For the sake of being interesting to the audience, their exploits tend to be on the flashy side, and Mad Science is not out of the question. A Kid Scientist is often a Child Prodigy or a Teen Genius, but it's not required. They may be Innocent Prodigies, Adorably Precocious Children, or Constantly Curious.
Examples:Anime and Manga