99 Boss is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The protagonist, Na Seon-wook, was born with the heart of a tiger. He was a troublemaker, but at the request of his parents, he hid his strength and transferred to Gukyang High School, a school located in a remote area that he thought would be quiet. However, it was a place where various old-fashioned cultures and dangerous people gathered. Seon-wook, who wanted to graduate quietly, eventually he couldn’t help but feel his hot blood and began educating them!