My Second Life as a Gang Leader

The protagonist finds himself in the Shanghai of the Republic of China era after a time-traveling journey, where he is confronted with debt collectors demanding payment. Sworn to protect his family in a dire situation, he inadvertently gets caught up in the feuds between rival gangs and the Japanese. He faces treacherous predicaments in his quest to save his friends and family, always with the timely assistance of a mysterious helper. In a twist of fate, he uncovers his heritage as the offspring of Shanghai's king, eradicates the Axe Gang, seizes leadership of the Green Gang, and ultimately ascends as the master of all gangs.