The concept of time plays a crucial role in shaping the narrative of "Tokyo Revengers" as it revolves around time travel and altering the past to change the future. The protagonist, Takemichi, uses his ability to travel back in time to prevent tragedies from occurring and to save the lives of his friends. The story explores the consequences of changing the past and the ripple effects it has on the present timeline, creating a complex and engaging narrative that revolves around the manipulation of time.