A Boy was born in the world of beings with animal features like a man with a dog ears and a dog tail and we call these beings Demi Humen. With their animal side they are able to unlock their animalistic abilities like great hearing sense of smell and sight. Also the unlock other skills you're faster more agile and stronger depending on what kind of animal species you are.
His Demi human animal side of species is a wolverine capable of defeating opponent larger than his size. His hidden ability special is also the more damage he received from his opponent the more stronger his physical body become.