Who is Jan Dapperste from This Earth of Mankind and what is their importance?

Jan Dapperste is a student at H.B.S. who is a Native who was adopted by Europeans. He is ashamed of his Dutch last name, since he is really Native. He is a friend of Minke's and ends up becoming involved in the Mellema family business. In the end, he is able to change his last name to a Javanese name.