Three-and-a-half-year-old Huo Suisui gets bound to a Mischief System and vows to become the ultimate troublemaker! On her very first day, her father's most treasured antique vase shatters into pieces right in front of her, only for a listening device to roll out from the fragments. By sheer accident, she saves the Huo family's trump card in their business negotiations! When she brings bitter melon juice to her frail eldest brother, she unexpectedly uncovers something fishy about his medicinal supplements. When she rushes to the film set to cause trouble for her third brother, she ends up clearing his name of the rumors. The more trouble she causes, the more touched her family becomes, and her four brothers take turns showering her with love. The System is on the verge of a breakdown: 'Host, you've turned another prank into something good!' What kind of disaster will she cause next?