My Mobster Girlfriend is a Manga/Manhwa/Manhua in english language, Harem series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Zhang Nan, the young master of the Hidden Dragon Family, wanted to become an ordinary person, but he was sent to the aristocratic training school by his grandfather. When he was assigned to an all-female class by a confused teacher, Zhang Nan finds himself tortured by these heirs to the brink of dropping out..