Boss in School is a Manga/Manhwa/Manhua in (English/Raw) 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

Seth Kwon was a born fighter. But due to his promise with his mother, he decides to stop fighting, even in self-defense… Everything changes when his father dies and leaves him with a single message: “stop getting your ass kicked”.