For her ill grandmother, the female lead's immense strength gets her fired from a boxing gym. Her strength catches the male lead's eye; he hires her as his personal bodyguard. She saves his life, moving in for 24-hour security. The picky CEO and strong woman have misadventures. She learns his parents died suspiciously, his grandfather was injured, suspecting the Hale family's adopted son. As they expose the cunning adopted son, the male lead meets her grandmother.