I only remember a part of the plot of the novel, but I don't know the name of the main character. Are there any recommended novels?

The female protagonist's father was from a gang. She was not her biological child. She was good friends with the male protagonist's sister. She had a boyfriend and the two of them were very much in love. However, the male protagonist's parents did not like the female protagonist. Because of the identity of the female protagonist's father, there was a time when the male protagonist went to pick up his sister from school. The female protagonist accidentally bumped into the male protagonist, and the male protagonist decided on him. Later, the male protagonist began to plan to secretly give the evidence of the female protagonist's father to the female protagonist's boyfriend's parents. Later, the female protagonist's father went to jail. The female protagonist's boyfriend was forced to break up with her. In order to save her father, she went to the male protagonist because only the male protagonist had the ability to save her father. Later, she promised to live with him. The latter part of the story was about the male protagonist's sister, the female protagonist's good friend, and another man. The man seemed to be a very powerful person. He seemed to be the boss of a gang and was involved in smuggling. It was very dangerous. The male protagonist began to object and locked his sister at home. Later, the younger sister still ran out. After a series of events, the man gradually changed and gave up his background as a gangster. The ending of these two characters was good.