Used book – Code name Komiko, Volume 1: In the Night of Hong Kong, Naomi Paul

Lian, 16, is a well-bred girl, a brilliant student and a virtuoso violinist. She lives in Hong Kong with her parents. But she leads a double life: she is part of an activist hacker group, the 04/06, who fight against injustice and corruption. When she learns that her father's company is partnering with an American textile multinational, she decides to fight to defend the oppressed workers. She uncovers a vast mafia organization involving both political authorities and the police.